2002
KN4LF DAILY
HF/MF FREQUENCY
RADIO PROPAGATION OUTLOOK ARCHIVE
KN4LF HIGH/MEDIUM FREQUENCY RADIO
PROPAGATION THEORY NOTES
Layman Level Explanations Of Seemingly Mysterious HF/MF Propagation Occurrences
KN4LF SOLAR SPACE WEATHER GEOMAGNETIC PROPAGATION ARCHIVE HOME
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-37
Published 8:00 PM EST 02/12/20 For 02/12/21-02/12/27.
PROPAGATION-
Expect good domestic propagation conditions on east-west paths and fair
on north south paths in the northern hemisphere out to approximately 1050
miles.
Expect fair domestic propagation conditions on east-west paths and poor on
north south paths in the southern hemisphere out to approximately 1050
miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be poor to fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be poor.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in excess of approximately 3000 miles should be fair to good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in excess of approximately 3000 miles should be fair to good.
QRN-
During the outlook period there will be "high" lightning induced QRN levels in low latitude
areas of the northern hemisphere due to proximity of the Inter Tropical Convergence Zone (ITCZ).
Northern hemisphere mid latitude regions can expect "moderate to occasionally high" lightning
induced QRN tied to cold season thunderstorms, cold/warm/occluded fronts and associated
extra-tropical cold core low pressure systems. These weather systems are currently being
enhanced by the moderate level El Nino ocean water temperature anomaly.
Northern hemisphere high latitude regions can expect "low to occasionally moderate" lightning
induced QRN tied to cold season thunderstorms, cold/warm/occluded fronts and associated
extra-tropical cold core low pressure systems. These weather systems are currently being
enhanced by the moderate level El Nino ocean water temperature anomaly.
During the outlook period there will be "high" lightning induced QRN levels
in low latitude areas of the southern hemisphere tied to warm season thunderstorms and tropical
systems.
Southern hemisphere mid latitude regions can expect "moderate to high" lightning induced QRN,
tied to warm season thunderstorms and tropical systems.
Southern hemisphere high latitude regions can expect "moderate" lightning induced QRN,
tied to warm season thunderstorms and tropical systems.
Here are some general guidelines concerning correlation of space weather and
propagation indices to actual expected HF/MF propagation conditions.
1.) Dropping indices numbers are better.
2.) Solar flux under 150 okay, under 100 better, 70 is best for E layer
multi hop.
2a.) For high frequencies (HF) solar flux of 100 is okay, 150 better, above 200
best.
3.) Solar flux of at least 100 for E valley-F layer ducting mechanism.
4.) Previous 24 hour Ap index under 10, under 7 for several days
consecutively is best.
5.) Previous 3 hour Kp index under 3 for mid latitude paths, under 2 for
high latitude paths, 0-1
for several days consecutively is best.
6.) Energetic protons no greater then 10 MeV (10+0) for 160/120 meters and
no greater then (10-1)
on MF broadcast band.
7.) Background x-ray flux levels less than C2 for several days consecutively
for 160/120 meters and
less then C1 for MF broadcast band.
8.) No current STRATWARM alert.
9.) IMF Bz with a negative sign, indicates a better chance of high latitude
path auroral absorption/unpredictable refraction or scattering of MF RF signals, when the
Kp is above 3.
SPACE WEATHER INDICES DURING THE PAST 7 DAY PERIOD, SPACE WEATHER INDICES EXPECTED DURING
THE 7 DAY OUTLOOK PERIOD AND EXPLANATIONS OF THEIR IMPACT ON ANTICIPATED PROPAGATION CONDITIONS.
ENERGETIC PROTON FLUX-
During the previous 7 day period one elevated energetic proton flux event
of >10 MeV (10+0) occurred. This event reached a level of (10+1) on 02/12/19-20
and was associated with an M2.7 level proton flare that was released from solar
flare region 10229.
During the 7 day outlook period the probability of an elevated energetic
proton flux event >10 MeV (10+0) is placed at 30%.
An elevated energetic proton flux level greater then (10+0) on 160 meters
and greater then (10-1) on the medium frequency broadcast band creates
noticeably increased winter time day and year round night time D layer
absorption of medium wave frequencies, especially on
high latitude propagation paths but it can also negatively impact mid
latitudes, depending on the intensity of the event.
Elevated energetic proton events too small to be categorized as a Polar Cap
Absorption event (PCA) can still impact high and mid level medium frequency
propagation paths in the form of excessive D layer absorption. This fact is
still stubbornly opposed by some otherwise very knowledgeable space weather
physicists over dependent on high latitude threshold Riometer readings.
((((Note, high latitude medium frequency radio propagation paths can still
be disturbed for days and up to weeks, following the end of an official >10
MeV (10+0) proton event.))))
SOLAR FLUX-
During the previous 7 day period the daily solar flux levels ranged between
245 and 179.
During the outlook period the daily solar flux values should range
between approximately 200 and 160.
Elevated background X-ray flux levels can impact propagation of medium
frequency signals in a negative manner. Background X-ray flux levels of C1
or greater creates increased D-layer absorption of 160 and 120 meter signals
and B9 or greater creates increased D-layer absorption of AM broadcast band signals.
High solar flux values are generally considered to be detrimental to
propagation of medium frequency signals both domestic and Trans Atlantic
(TA) & Trans Pacific (TP), as more absorption can be present via the
transmitted signals' two trips through the D layer at the takeoff and arrival points.
Most "strong" longer haul medium frequency DX signals in excess of 3000
miles is via the E Valley-F layer ducting and/or Chordal Hop propagation
modes. Therefore high solar flux values can aid in long haul medium frequency
propagation paths in excess of 3000 miles, as a high solar flux value ensures a
strong F layer part of the E Valley-F layer duct or Chordal Hop propagation mechanism.
However high solar activity in the form of increased ionization created by
Ultraviolet and X-Ray radiation can fill in the E Valley region and
interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F
layer duct is closed on one or both ends of a propagation path and the transmitted
MF RF signal only propagates between the E layer and land/ocean surface, with a higher
angle and more loss.
SOLAR FLARES & SUNSPOT GROUP REGIONS-
During the previous 7 day period 7 M class solar flares occurred. The
largest was an M6.8 solar flare on 02/12/20 at 1318 UTC and was associated
with solar region 10226.
Sunspot region #10226 at S28W28 is in geo-effective (Earth facing) position,
contains a beta-gamma-delta class magnetic signature and harbors energy for huge X
class and large M class solar flares.
Sunspot region #10224 at S14W21, #10229 at N19W03, and #10230 at S08E32 contain a beta-gamma
class magnetic signatures and harbor energy for large M class solar flares.
Solar flare forecast during the seven day period.
C- 100%
M- 70%
X- 30%
A C4 or higher class solar flare "can" elevate the proton flux above 10 MeV
(10+0) and initiate large scale high and mid latitude propagation path absorption
on the AM broadcast band, 160 and 120 meters, both stateside and DX, as a transfer
of increased density and RF signal absorption from the day side D layer to night
side of the ionosphere occurs through high level neutral winds.
Unfortunately even smaller C3 solar flares can create hour to hour and night
to night variations in signal strength on medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths tend to open up after a significant period of time passes without an
elevated energetic proton event of >10 MeV (10+0). This fact is still stubbornly
opposed by some otherwise very knowledgeable space weather physicists over dependent
on high latitude threshold Riometer readings.
Openings also occur when the solar background x-ray level falls back to
below C2 for 160 and 120 meters and below C1 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
During the previous 7 day period one geo-effective (Earth facing) Coronal Mass
Ejection occurred on 02/12/19 at 2200 UTC and was associated with an M2.7 level
proton flare that was released from solar flare region 10229.
During the previous 7 day period a small Coronal Hole had been in a
geo-effective (Earth facing) position. It's related Solar Wind Stream
impacted the (IMF), for a short period of time with a Kp index of 3 (unsettled).
A SHORT LIVED Kp spike of 4 (Active) to 5 (Minor Storm) occurred on 02/12/19-20
in association with the M2.7 level proton flare that was released from solar
flare region 10229.
During the outlook period no new geo-effective (Earth facing) Coronal
Holes and related Solar Wind Streams are expected to impact the (IMF).
During the outlook period the probability of a geo-effective (Earth facing)
Coronal Mass Ejection (CME) is placed at 50%.
During the outlook period the probability of unsettled (Kp-3)
geomagnetic conditions is placed at 100%.
During the outlook period the probability of active (Kp-4)
geomagnetic conditions is placed at 90%.
During the outlook period the probability of at least a minor ionospheric
storm (Kp-5)(G1) is placed at 80%.
During the outlook period the probability of at least a moderate ionospheric
storm (Kp-6)(G2) is placed at 70%.
During the outlook period the probability of at least a strong ionospheric
storm (Kp-7+)(G3+) is placed at 60%.
G5 = Extreme - Kp = 9
G4 = Severe - Kp = 8
G3 = Strong - Kp = 7
G2 = Moderate - Kp = 6
G1 = Minor - Kp = 5
Active - Kp = 4
Unsettled - Kp = 3
During the outlook period the probability of a visible high latitude Aurora
display is placed at 100%, mid latitude 60%.
On 02/12/20 at 2037 UTC the Bz was 4.5 nt south.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
the Sun's IMF polarity, forecasts a positive (+) polarity between 02/12/21-27.
When the polarity of the IMF is negative a visible mid latitude Aurora
display is likely when a CME strikes the Earth's magnetic field. When the
polarity of the IMF is
positive a visible mid latitude Aurora display is unlikely as a CME strikes
the Earth's magnetic
field.
A Geomagnetic or Ionospheric Storm is a worldwide disturbance of the earth's
magnestosphere induced by
the Sun's interplanetary magnetic field (IMF), distinct from regular diurnal
variations.
A Coronal Mass Ejection is the name given to an ejection of a large amount
of matter from the Sun's outer atmosphere or corona. These ejections
typically comprise millions of
tons of material in the form of charged particles, and can be seen because
the material reflects
sunlight. When one of these ejections is directed towards the Earth (or
conversely, directly away
from the Earth), it looks like a roughly circular "halo" surrounding the
Sun.
The "Halo CME's" then are those CME's which are more likely to impact the
Earth than those which are shot out at right angles to the Earth-Sun line.
Energetic protons
emitted during CME's play a major role in increased day time and night-time
D-layer absorption of
mediumwave frequencies.
Coronal Mass Ejections were once thought to be completely initiated by solar
flares. However it is now known that many (CME's) are not associated with
Solar Flares. If a (CME)
collides with the Earth, it can excite a Geomagnetic Storm if the polarity
of the IMF has a
negative sign. We must be vigilant in watching for geoeffective (CME's), in
order to not be caught
by surprise with a seemingly sudden and unexpected Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in
magnetic latitude and generally begins having a negative impact on high
latitude medium frequency
propagation paths. A Kp index of 5 or higher begins to have a negative
impact on high latitude high
frequency shortwave propagation paths. However at times skewed path
propagation conditions can
compensate for high
latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period increased winter like day and year round
night time D layer absorption of medium frequency signals tied to stratospheric
warming in the northern hemisphere is possible, due to a large scale movement of
Arctic air across the North Pole from Siberian Russia into Canada.
In the nearer term of 7-14 days we will return to a negative North Atlantic
Oscillation (NAO) and Positive West Negative East (PNA) upper air height anomaly
pattern. This means a big ridge in the west all the way into the Yukon region of Canada
and a deep trough in the eastern U.S.down into the Yucatan region of Mexico and another
ridge in the western North Atlantic Ocean. This pattern is also called
a dual blocking ridge. This pattern taps Siberian Arctic air across the
North Pole and sends it rushing south, increasing the chances of stratospheric warming.
As the stratosphere lies below the ionosphere, which
is at mesosphere and thermosphere height, you would not expect to see
stratospheric warming effect medium frequency propagation in any way BUT
medium frequency signals do propagate off of temperature inversions
and moisture discontinuities and a temperature inversion is involved
with stratospheric warming. So it's probable that a medium frequency
signal could do any number of things when scattering off of a temperature
inversion, at any height. Unfortunately though some otherwise very
knowledgeable Physicists stubbornly resist this concept.
Also stratospheric warming (STRATWARM) has a negative effect on medium
frequency propagation, due to increasing medium frequency radio wave
absorption by the D layer, via
upward propagating Internal Gravity Waves (IGW).
This phenomenon also occurs in southern hemisphere winter but seems to be
less pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-37
Published 8:00 PM EST 02/12/20 For 02/12/21-02/12/27.
PROPAGATION-
Expect good domestic propagation conditions on east-west paths and fair
on north south paths in the northern hemisphere out to approximately 1050
miles.
Expect fair domestic propagation conditions on east-west paths and poor on
north south paths in the southern hemisphere out to approximately 1050
miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be poor to fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be poor.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in excess of approximately 3000 miles should be fair to good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in excess of approximately 3000 miles should be fair to good.
QRN-
During the outlook period there will be "high" lightning induced QRN levels in low latitude
areas of the northern hemisphere due to proximity of the Inter Tropical Convergence Zone (ITCZ).
Northern hemisphere mid latitude regions can expect "moderate to occasionally high" lightning
induced QRN tied to cold season thunderstorms, cold/warm/occluded fronts and associated
extra-tropical cold core low pressure systems. These weather systems are currently being
enhanced by the moderate level El Nino ocean water temperature anomaly.
Northern hemisphere high latitude regions can expect "low to occasionally moderate" lightning
induced QRN tied to cold season thunderstorms, cold/warm/occluded fronts and associated
extra-tropical cold core low pressure systems. These weather systems are currently being
enhanced by the moderate level El Nino ocean water temperature anomaly.
During the outlook period there will be "high" lightning induced QRN levels
in low latitude areas of the southern hemisphere tied to warm season thunderstorms and tropical
systems.
Southern hemisphere mid latitude regions can expect "moderate to high" lightning induced QRN,
tied to warm season thunderstorms and tropical systems.
Southern hemisphere high latitude regions can expect "moderate" lightning induced QRN,
tied to warm season thunderstorms and tropical systems.
Here are some general guidelines concerning correlation of space weather and
propagation indices to actual expected HF/MF propagation conditions.
1.) Dropping indices numbers are better.
2.) Solar flux under 150 okay, under 100 better, 70 is best for E layer
multi hop.
2a.) For high frequencies (HF) solar flux of 100 is okay, 150 better, above 200
best.
3.) Solar flux of at least 100 for E valley-F layer ducting mechanism.
4.) Previous 24 hour Ap index under 10, under 7 for several days
consecutively is best.
5.) Previous 3 hour Kp index under 3 for mid latitude paths, under 2 for
high latitude paths, 0-1
for several days consecutively is best.
6.) Energetic protons no greater then 10 MeV (10+0) for 160/120 meters and
no greater then (10-1)
on MF broadcast band.
7.) Background x-ray flux levels less than C2 for several days consecutively
for 160/120 meters and
less then C1 for MF broadcast band.
8.) No current STRATWARM alert.
9.) IMF Bz with a negative sign, indicates a better chance of high latitude
path auroral absorption/unpredictable refraction or scattering of MF RF signals, when the
Kp is above 3.
SPACE WEATHER INDICES DURING THE PAST 7 DAY PERIOD, SPACE WEATHER INDICES EXPECTED DURING
THE 7 DAY OUTLOOK PERIOD AND EXPLANATIONS OF THEIR IMPACT ON ANTICIPATED PROPAGATION CONDITIONS.
ENERGETIC PROTON FLUX-
During the previous 7 day period one elevated energetic proton flux event
of >10 MeV (10+0) occurred. This event reached a level of (10+1) on 02/12/19-20
and was associated with an M2.7 level proton flare that was released from solar
flare region 10229.
During the 7 day outlook period the probability of an elevated energetic
proton flux event >10 MeV (10+0) is placed at 30%.
An elevated energetic proton flux level greater then (10+0) on 160 meters
and greater then (10-1) on the medium frequency broadcast band creates
noticeably increased winter time day and year round night time D layer
absorption of medium wave frequencies, especially on
high latitude propagation paths but it can also negatively impact mid
latitudes, depending on the intensity of the event.
Elevated energetic proton events too small to be categorized as a Polar Cap
Absorption event (PCA) can still impact high and mid level medium frequency
propagation paths in the form of excessive D layer absorption. This fact is
still stubbornly opposed by some otherwise very knowledgeable space weather
physicists over dependent on high latitude threshold Riometer readings.
((((Note, high latitude medium frequency radio propagation paths can still
be disturbed for days and up to weeks, following the end of an official >10
MeV (10+0) proton event.))))
SOLAR FLUX-
During the previous 7 day period the daily solar flux levels ranged between
245 and 179.
During the outlook period the daily solar flux values should range
between approximately 200 and 160.
Elevated background X-ray flux levels can impact propagation of medium
frequency signals in a negative manner. Background X-ray flux levels of C1
or greater creates increased D-layer absorption of 160 and 120 meter signals
and B9 or greater creates increased D-layer absorption of AM broadcast band signals.
High solar flux values are generally considered to be detrimental to
propagation of medium frequency signals both domestic and Trans Atlantic
(TA) & Trans Pacific (TP), as more absorption can be present via the
transmitted signals' two trips through the D layer at the takeoff and arrival points.
Most "strong" longer haul medium frequency DX signals in excess of 3000
miles is via the E Valley-F layer ducting and/or Chordal Hop propagation
modes. Therefore high solar flux values can aid in long haul medium frequency
propagation paths in excess of 3000 miles, as a high solar flux value ensures a
strong F layer part of the E Valley-F layer duct or Chordal Hop propagation mechanism.
However high solar activity in the form of increased ionization created by
Ultraviolet and X-Ray radiation can fill in the E Valley region and
interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F
layer duct is closed on one or both ends of a propagation path and the transmitted
MF RF signal only propagates between the E layer and land/ocean surface, with a higher
angle and more loss.
SOLAR FLARES & SUNSPOT GROUP REGIONS-
During the previous 7 day period 7 M class solar flares occurred. The
largest was an M6.8 solar flare on 02/12/20 at 1318 UTC and was associated
with solar region 10226.
Sunspot region #10226 at S28W28 is in geo-effective (Earth facing) position,
contains a beta-gamma-delta class magnetic signature and harbors energy for huge X
class and large M class solar flares.
Sunspot region #10224 at S14W21, #10229 at N19W03, and #10230 at S08E32 contain a beta-gamma
class magnetic signatures and harbor energy for large M class solar flares.
Solar flare forecast during the seven day period.
C- 100%
M- 70%
X- 30%
A C4 or higher class solar flare "can" elevate the proton flux above 10 MeV
(10+0) and initiate large scale high and mid latitude propagation path absorption
on the AM broadcast band, 160 and 120 meters, both stateside and DX, as a transfer
of increased density and RF signal absorption from the day side D layer to night
side of the ionosphere occurs through high level neutral winds.
Unfortunately even smaller C3 solar flares can create hour to hour and night
to night variations in signal strength on medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths tend to open up after a significant period of time passes without an
elevated energetic proton event of >10 MeV (10+0). This fact is still stubbornly
opposed by some otherwise very knowledgeable space weather physicists over dependent
on high latitude threshold Riometer readings.
Openings also occur when the solar background x-ray level falls back to
below C2 for 160 and 120 meters and below C1 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
During the previous 7 day period one geo-effective (Earth facing) Coronal Mass
Ejection occurred on 02/12/19 at 2200 UTC and was associated with an M2.7 level
proton flare that was released from solar flare region 10229.
During the previous 7 day period a small Coronal Hole had been in a
geo-effective (Earth facing) position. It's related Solar Wind Stream
impacted the (IMF), for a short period of time with a Kp index of 3 (unsettled).
A SHORT LIVED Kp spike of 4 (Active) to 5 (Minor Storm) occurred on 02/12/19-20
in association with the M2.7 level proton flare that was released from solar
flare region 10229.
During the outlook period no new geo-effective (Earth facing) Coronal
Holes and related Solar Wind Streams are expected to impact the (IMF).
During the outlook period the probability of a geo-effective (Earth facing)
Coronal Mass Ejection (CME) is placed at 50%.
During the outlook period the probability of unsettled (Kp-3)
geomagnetic conditions is placed at 100%.
During the outlook period the probability of active (Kp-4)
geomagnetic conditions is placed at 90%.
During the outlook period the probability of at least a minor ionospheric
storm (Kp-5)(G1) is placed at 80%.
During the outlook period the probability of at least a moderate ionospheric
storm (Kp-6)(G2) is placed at 70%.
During the outlook period the probability of at least a strong ionospheric
storm (Kp-7+)(G3+) is placed at 60%.
G5 = Extreme - Kp = 9
G4 = Severe - Kp = 8
G3 = Strong - Kp = 7
G2 = Moderate - Kp = 6
G1 = Minor - Kp = 5
Active - Kp = 4
Unsettled - Kp = 3
During the outlook period the probability of a visible high latitude Aurora
display is placed at 100%, mid latitude 60%.
On 02/12/20 at 2037 UTC the Bz was 4.5 nt south.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
the Sun's IMF polarity, forecasts a positive (+) polarity between 02/12/21-27.
When the polarity of the IMF is negative a visible mid latitude Aurora
display is likely when a CME strikes the Earth's magnetic field. When the
polarity of the IMF is
positive a visible mid latitude Aurora display is unlikely as a CME strikes
the Earth's magnetic
field.
A Geomagnetic or Ionospheric Storm is a worldwide disturbance of the earth's
magnestosphere induced by
the Sun's interplanetary magnetic field (IMF), distinct from regular diurnal
variations.
A Coronal Mass Ejection is the name given to an ejection of a large amount
of matter from the Sun's outer atmosphere or corona. These ejections
typically comprise millions of
tons of material in the form of charged particles, and can be seen because
the material reflects
sunlight. When one of these ejections is directed towards the Earth (or
conversely, directly away
from the Earth), it looks like a roughly circular "halo" surrounding the
Sun.
The "Halo CME's" then are those CME's which are more likely to impact the
Earth than those which are shot out at right angles to the Earth-Sun line.
Energetic protons
emitted during CME's play a major role in increased day time and night-time
D-layer absorption of
mediumwave frequencies.
Coronal Mass Ejections were once thought to be completely initiated by solar
flares. However it is now known that many (CME's) are not associated with
Solar Flares. If a (CME)
collides with the Earth, it can excite a Geomagnetic Storm if the polarity
of the IMF has a
negative sign. We must be vigilant in watching for geoeffective (CME's), in
order to not be caught
by surprise with a seemingly sudden and unexpected Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in
magnetic latitude and generally begins having a negative impact on high
latitude medium frequency
propagation paths. A Kp index of 5 or higher begins to have a negative
impact on high latitude high
frequency shortwave propagation paths. However at times skewed path
propagation conditions can
compensate for high
latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period increased winter like day and year round
night time D layer absorption of medium frequency signals tied to stratospheric
warming in the northern hemisphere is possible, due to a large scale movement of
Arctic air across the North Pole from Siberian Russia into Canada.
In the nearer term of 7-14 days we will return to a negative North Atlantic
Oscillation (NAO) and Positive West Negative East (PNA) upper air height anomaly
pattern. This means a big ridge in the west all the way into the Yukon region of Canada
and a deep trough in the eastern U.S.down into the Yucatan region of Mexico and another
ridge in the western North Atlantic Ocean. This pattern is also called
a dual blocking ridge. This pattern taps Siberian Arctic air across the
North Pole and sends it rushing south, increasing the chances of stratospheric warming.
As the stratosphere lies below the ionosphere, which
is at mesosphere and thermosphere height, you would not expect to see
stratospheric warming effect medium frequency propagation in any way BUT
medium frequency signals do propagate off of temperature inversions
and moisture discontinuities and a temperature inversion is involved
with stratospheric warming. So it's probable that a medium frequency
signal could do any number of things when scattering off of a temperature
inversion, at any height. Unfortunately though some otherwise very
knowledgeable Physicists stubbornly resist this concept.
Also stratospheric warming (STRATWARM) has a negative effect on medium
frequency propagation, due to increasing medium frequency radio wave
absorption by the D layer, via
upward propagating Internal Gravity Waves (IGW).
This phenomenon also occurs in southern hemisphere winter but seems to be
less pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-36
Published 11:00 PM EST 02/12/13 For 02/12/14-02/12/20.
Overall medium frequency propagation conditions should continue to be continue good.
Due to the low sun angle in the northern hemisphere as we approach the Winter Solstice
D layer ionization is weaker and I've been observing skywave propagation of signals on
the AM broadcast band and 160 meters. WSM 650 and WSB 750 have
been coming in Q5 at local noon.
During the past 7 day period solar and geomagnetic conditions were basically quiet.
Why? The effects of the solar wind on the magnetosphere decreases as we approach
the Summer/Winter solstice and increases at the Fall/Spring Equinox. Why? Basically it's the
orientation of Earth's magnetic field with respect to the interplanetary magnetic field
within the solar wind. When solar material and shock waves reach Earth their effects may
be enhanced or dampened depending on the angle at which they arrive.
Expect good domestic propagation conditions on east-west paths and fair to
good on north south paths in the northern hemisphere out to approximately 1050
miles.
Expect good domestic propagation conditions on east-west paths and fair on
north south paths in the southern hemisphere out to approximately 1050
miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair to good.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair to good.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in excess of approximately 3000 miles should be good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in excess of approximately 3000 miles should be good.
During the outlook period there will be "moderate to occasionally high" lightning induced
QRN levels in low latitude areas of the northern hemisphere tied to cold season
thunderstorms, cold/warm/occluded fronts and associated extra-tropical cold core
low pressure systems. These weather systems are currently being enhanced by the
moderate level El Nino ocean water temperature anomaly.
Northern hemisphere mid latitude regions can expect "moderate" lightning induced QRN.
Northern hemisphere high latitude regions can expect "low to occasionally moderate" lightning
induced QRN.
During the outlook period there will be "high" lightning induced QRN levels
in low latitude areas of the southern hemisphere tied to warm season thunderstorms and tropical
systems.
Southern hemisphere mid latitude regions can expect "moderate to high" lightning induced QRN.
Southern hemisphere high latitude regions can expect "moderate" lightning
induced QRN.
Here are some general guidelines concerning correlation of space weather and
propagation indices to actual expected HF/MF propagation conditions.
1.) Dropping indices numbers are better.
2.) Solar flux under 150 okay, under 100 better, 70 is best for E layer
multi hop.
2a.) For high frequencies (HF) solar flux of 100 is okay, 150 better, above 200
best.
3.) Solar flux of at least 100 for E valley-F layer ducting mechanism.
4.) Previous 24 hour Ap index under 10, under 7 for several days
consecutively is best.
5.) Previous 3 hour Kp index under 3 for mid latitude paths, under 2 for
high latitude paths, 0-1
for several days consecutively is best.
6.) Energetic protons no greater then 10 MeV (10+0) for 160/120 meters and
no greater then (10-1)
on MF broadcast band.
7.) Background x-ray flux levels less than C2 for several days consecutively
for 160/120 meters and
less then C1 for MF broadcast band.
8.) No current STRATWARM alert.
9.) IMF Bz with a negative sign, indicates a better chance of high latitude
path auroral absorption/unpredictable refraction or scattering of MF RF signals, when the
Kp is above 3.
SPACE WEATHER INDICES EXPECTED DURING THE 7 DAY PERIOD AND EXPLANATIONS
OF THEIR IMPACT ON ANTICIPATED PROPAGATION CONDITIONS.
ENERGETIC PROTON FLUX-
During the previous 7 day period no elevated energetic proton flux events
of 10 MeV (10+0) occurred.
During the 7 day outlook period the probability of an elevated energetic
proton flux event >10 MeV (10+0) is placed at 10%.
An elevated energetic proton flux level greater then (10+0) on 160 meters
and greater then (10-1) on the medium frequency broadcast band creates
noticeably increased winter time day and year round night time D layer
absorption of medium wave frequencies, especially on
high latitude propagation paths but it can also negatively impact mid
latitudes, depending on the intensity of the event.
Elevated energetic proton events too small to be categorized as a Polar Cap
Absorption event (PCA) can still impact high and mid level medium frequency
propagation paths in the form of excessive D layer absorption. This fact is
still stubbornly opposed by some otherwise
very knowledgeable space weather physicists over dependent on high latitude
threshold Riometer readings.
((((Note, high latitude medium frequency radio propagation paths can still
be disturbed for days and up to weeks, following the end of an official >10
MeV (10+0) proton
event.))))
SOLAR FLUX-
During the previous 7 day period the daily solar flux levels ranged between
170 and 144.
During the same period one year ago the daily solar flux ranged between 247 and 223.
During the outlook period the daily solar flux values should range
between approximately 175 and 145.
Elevated background X-ray flux levels can impact propagation of medium
frequency signals in a negative manner. Background X-ray flux levels of C2
or greater creates increased D-layer absorption of 160 and 120 meter signals
and C1 or greater creates increased D-layer absorption of AM broadcast band signals.
High solar flux values are generally considered to be detrimental to
propagation of medium frequency signals both domestic and Trans Atlantic
(TA) & Trans Pacific (TP), as more absorption can be present via the
transmitted signals' two trips through the D layer at the takeoff and arrival points.
Most "strong" longer haul medium frequency DX signals in excess of 3000
miles is via the E Valley-F layer ducting and/or Chordal Hop propagation
modes. Therefore high solar flux values can aid in long haul medium frequency
propagation paths in excess of 3000 miles, as a high solar flux value ensures a
strong F layer part of the E Valley-F layer duct or Chordal Hop propagation mechanism.
However high solar activity in the form of increased ionization created by
Ultraviolet and X-Ray radiation can fill in the E Valley region and
interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F
layer duct is closed on one or both ends of a propagation path and the transmitted
MF RF signal only propagates between the E layer and land/ocean surface, with a higher
angle and more loss.
SOLAR FLARES & SUNSPOT GROUP REGIONS-
During the previous 7 day period no M class solar flares occurred. The
largest was a C9.0 solar flare on 02/12/10 at 1219-1229 UTC.
Sunspot region #10224 at S17E61 contains a beta-gamma class magnetic signature and harbors energy
for large M class solar flares.
Solar flare forecast during the seven day period.
C- 100%
M- 50%
X- 05%
A C4 or higher class solar flare "can" elevate the proton flux above 10 MeV
(10+0) and initiate
large scale high and mid latitude propagation path absorption on the AM
broadcast band, 160 and 120
meters, both stateside and DX, as a transfer of increased density and RF
signal absorption from the
day side D layer to night side of the ionosphere occurs through high level
neutral winds.
Unfortunately even smaller C3 solar flares can create hour to hour and night
to night variations in
signal strength on medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths tend to open up after a significant period of time passes without an
elevated energetic
proton event of >10 MeV (10+0). This fact is still stubbornly opposed by
some otherwise very
knowledgeable space weather physicists over dependent on high latitude
threshold Riometer readings.
Openings also occur when the solar background x-ray level falls back to or
below C1 for 160 and 120 meters and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
No geo-effective (Earth facing) Coronal Mass Ejections Occurred.
During the previous 7 day period a small Coronal Hole had been in a
geo-effective (Earth facing) position. It's related Solar Wind Stream
impacted the (IMF), for a short period between 02/12/07-08 with a
Kp index of 3 (unsettled) to 4 (active).
During the outlook period another small geo-effective (Earth facing) Coronal
Hole and related Solar Wind Stream is expected to impact the (IMF).
beginning on 02/12/15-16.
During the outlook period the probability of a geo-effective (Earth facing)
Coronal Mass Ejection (CME) is placed at 10%.
During the outlook period the probability of unsettled (Kp-3)
geomagnetic conditions is placed at 100%.
During the outlook period the probability of active (Kp-4)
geomagnetic conditions is placed at 60%.
During the outlook period the probability of at least a minor ionospheric
storm (Kp-5)(G1) is placed at 30%.
During the outlook period the probability of at least a moderate ionospheric
storm (Kp-6)(G2) is placed at 20%.
During the outlook period the probability of at least a strong ionospheric
storm (Kp-7+)(G3+) is placed at 10%.
G5 = Extreme - Kp = 9
G4 = Severe - Kp = 8
G3 = Strong - Kp = 7
G2 = Moderate - Kp = 6
G1 = Minor - Kp = 5
Active - Kp = 4
Unsettled - Kp = 3
During the outlook period the probability of a visible high latitude Aurora
display is placed at 50%, mid latitude 10%.
On 02/12/13 at 1618 UTC the Bz is 0.9 nt north.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
the Sun's IMF polarity, forecasts a negative (-) polarity between 02/12/14-20.
When the polarity of the IMF is negative a visible mid latitude Aurora
display is likely when a CME strikes the Earth's magnetic field. When the
polarity of the IMF is
positive a visible mid latitude Aurora display is unlikely as a CME strikes
the Earth's magnetic
field.
A Geomagnetic or Ionospheric Storm is a worldwide disturbance of the earth's
magnestosphere induced by
the Sun's interplanetary magnetic field (IMF), distinct from regular diurnal
variations.
A Coronal Mass Ejection is the name given to an ejection of a large amount
of matter from the Sun's outer atmosphere or corona. These ejections
typically comprise millions of
tons of material in the form of charged particles, and can be seen because
the material reflects
sunlight. When one of these ejections is directed towards the Earth (or
conversely, directly away
from the Earth), it looks like a roughly circular "halo" surrounding the
Sun.
The "Halo CME's" then are those CME's which are more likely to impact the
Earth than those which are shot out at right angles to the Earth-Sun line.
Energetic protons
emitted during CME's play a major role in increased day time and night-time
D-layer absorption of
mediumwave frequencies.
Coronal Mass Ejections were once thought to be completely initiated by solar
flares. However it is now known that many (CME's) are not associated with
Solar Flares. If a (CME)
collides with the Earth, it can excite a Geomagnetic Storm if the polarity
of the IMF has a
negative sign. We must be vigilant in watching for geoeffective (CME's), in
order to not be caught
by surprise with a seemingly sudden and unexpected Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in
magnetic latitude and generally begins having a negative impact on high
latitude medium frequency
propagation paths. A Kp index of 5 or higher begins to have a negative
impact on high latitude high
frequency shortwave propagation paths. However at times skewed path
propagation conditions can
compensate for high
latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period increased winter like day and year round
night time D layer absorption of medium frequency signals tied to stratospheric
warming in the northern hemisphere is possible, due to a large scale movement of
Arctic air across the North Pole from Siberian Russia into Canada.
In the nearer term of 7-14 days we will return to a negative North Atlantic
Oscillation (NAO) and Positive West Negative East (PNA) upper air height anomaly
pattern. This means a big ridge in the west all the way into the Yukon region of Canada
and a deep trough in the eastern U.S.down into the Yucatan region of Mexico and another
ridge in the western North Atlantic Ocean. This pattern is also called
a dual blocking ridge. This pattern taps Siberian Arctic air across the
North Pole and sends it rushing south, increasing the chances of stratospheric warming.
As the stratosphere lies below the ionosphere, which
is at mesosphere and thermosphere height, you would not expect to see
stratospheric warming effect medium frequency propagation in any way BUT
medium frequency signals do propagate off of temperature inversions
and moisture discontinuities and a temperature inversion is involved
with stratospheric warming. So it's probable that a medium frequency
signal could do any number of things when scattering off of a temperature
inversion, at any height. Unfortunately though some otherwise very
knowledgeable Physicists stubbornly resist this concept.
Also stratospheric warming (STRATWARM) has a negative effect on medium
frequency propagation, due to increasing medium frequency radio wave
absorption by the D layer, via
upward propagating Internal Gravity Waves (IGW).
This phenomenon also occurs in southern hemisphere winter but seems to be
less pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-35
Published 4:00 PM EST 02/12/06 For 02/12/07-02/12/13.
Effective today I will begin producing and publishing this propagation outlook on Friday
afternoons at 4:00 EST, 2100 UTC. This one coincides with the ARRL 160-Meter Contest.
Overall medium frequency propagation conditions should be good.
Expect good domestic propagation conditions on east-west paths and fair to good on
north south paths in the northern hemisphere out to approximately 1050 miles.
Expect good domestic propagation conditions on east-west paths and fair on
north south paths in the southern hemisphere out to approximately 1050 miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be fair to good.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be fair.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be fair to good.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions
in excess of approximately 3000 miles should be good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions
in excess of approximately 3000 miles should be good.
During the outlook period there will be "moderate to high" lightning induced QRN levels in mid
latitude areas of the northern hemisphere tied to warm and cold season thunderstorms, tropical
systems, cold/warm/occluded fronts associated with extra-tropical cold core low pressure systems.
High latitude regions can expect “low to occasionally moderate” lightning induced QRN.
During the outlook period there will be "high" lightning induced QRN levels in mid latitude areas
of the southern hemisphere tied to warm season thunderstorms and tropical systems and to a lesser
extent cold/warm/occluded fronts associated with extra-tropical cold core low pressure systems.
High latitude regions can expect “low to occasionally moderate” lightning induced QRN.
High lightning induced QRN in association with year round thunderstorm activity will continue in
the vicinity of the northern and southern tropical ITCZ and across equatorial regions.
Here are some general guidelines concerning correlation of space weather and propagation indices
to actual expected MF propagation conditions.
1.) Dropping indices numbers are better.
2.) Solar flux under 150 okay, under 100 better, 70 is best for E layer multi hop.
2A.) For high frequencies solar flux of 100 is okay, 150 better, above 200 best.
3.) Solar flux of at least 100 for E valley-F layer ducting mechanism.
4.) Previous 24 hour Ap index under 10, under 7 for several days consecutively is best.
5.) Previous 3 hour Kp index under 3 for mid latitude paths, under 2 for high latitude paths, 0-1
for several days consecutively is best.
6.) Energetic protons no greater then 10 MeV (10+0) for 160/120 meters and no greater then (10-1)
on MF broadcast band.
7.) Background x-ray flux levels less than C2 for several days consecutively for 160/120 meters and
less then C1 for MF broadcast band.
8.) No current STRATWARM alert.
9.) IMF Bz with a negative sign, indicates a better chance of high latitude path auroral
absorption/unpredictable refraction or scattering of MF RF signals, when the Kp is above 3.
SPACE WEATHER INDICES EXPECTED DURING THE SEVEN DAY PERIOD AND EXPLANATIONS OF THEIR IMPACT
ON EXPECTED PROPAGATION CONDITIONS.
ENERGETIC PROTON FLUX-
During the 7 day outlook period the probability of an elevated energetic
proton flux event >10 MeV (10+0) is placed at 10%.
During the previous 11 day period a weak and short lived elevated energetic
proton flux event of 10 MeV (10+0) occurred.
An elevated energetic proton flux level greater then (10+0) on 160 meters
and greater then (10-1) on the medium frequency broadcast band creates noticeably increased winter
time day and year round night time D layer absorption of medium wave frequencies, especially on
high latitude propagation paths but it can also negatively impact mid latitudes, depending on the
intensity of the event.
Elevated energetic proton events too small to be categorized as a Polar Cap
Absorption event (PCA) can still impact high and mid level medium frequency propagation paths in
the form of excessive D layer absorption. This fact is still stubbornly opposed by some otherwise
very knowledgeable space weather physicists over dependent on high latitude threshold Riometer readings.
((((Note, high latitude medium frequency radio propagation paths can still
be disturbed for days and up to weeks, following the end of an official >10 MeV (10+0) proton
event.))))
SOLAR FLUX-
During the previous 11 day period the daily solar flux levels ranged between 164 and 138.
During the month of November 2002 daily solar flux levels ranged between 204 and 138.
During the 7 day outlook period the daily solar flux values should range between approximately 180
and 145.
Elevated background X-ray flux levels can impact propagation of medium
frequency signals in a negative manner. Background X-ray flux levels of C2 or greater creates
increased D-layer absorption of 160 and 120 meter signals and C1 or greater creates increased
D-layer absorption of AM broadcast band signals.
High solar flux values are generally considered to be detrimental to
propagation of medium frequency signals both domestic and Trans Atlantic (TA) & Trans Pacific
(TP), as more absorption can be present via the transmitted signals' two trips through the D layer
at the takeoff and arrival points.
Most "strong" longer haul medium frequency DX signals in excess of 3000
miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high
solar flux values can aid in long haul medium frequency propagation paths in excess of 3000 miles,
as a high solar flux value ensures a strong F layer part of the E Valley-F layer duct or Chordal
Hop propagation mechanism.
However high solar activity in the form of increased ionization created by
Ultraviolet and X-Ray radiation can fill in the E Valley region and interfere with the E Valley-F
layer ducting mechanism. In a sense the E Valley-F layer duct is closed on one or both ends of a
propagation path and the transmitted MF RF signal only propagates between the E layer and
land/ocean surface, with a higher angle and more loss.
SOLAR FLARES & SUNSPOT GROUP REGIONS-
During the previous 11 day period only one M class solar flares occurred. It was and M2.2 which
occurred on 02/12/04 at 2100 UTC.
Sunspot region #10208 at N10W06 contains a beta-gamma class magnetic signature and harbors energy
for a large M class solar flares.
Solar flare forecast during the seven day period.
C- 100%
M- 40%
X- 05%
A C4 or higher class solar flare "can" elevate the proton flux above 10 MeV (10+0) and initiate
large scale high and mid latitude propagation path absorption on the AM broadcast band, 160 and 120
meters, both stateside and DX, as a transfer of increased density and RF signal absorption from the
day side D layer to night side of the ionosphere occurs through high level neutral winds.
Unfortunately even smaller C3 solar flares can create hour to hour and night to night variations in
signal strength on medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths tend to open up after a significant period of time passes without an elevated energetic
proton event of >10 MeV (10+0). This fact is still stubbornly opposed by some otherwise very
knowledgeable space weather physicists over dependent on high latitude threshold Riometer readings.
Openings also occur when the solar background x-ray level falls back to or
below C1 for 160 and 120 meters and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
No geo-effective (Earth facing) Coronal Mass Ejections Occurred.
During the previous 11 day period a small Coronal Hole had been in a geo-effective (Earth facing)
position. It's related Solar Wind Stream impacted the Earth's (IMF), with a Kp index of 4 (active).
During the outlook period another geo-effective (Earth facing) Coronal
Hole and related Solar Wind Stream is expected to impact the Earth's (IMF). Impact on the (IMF)
should begin on 02/12/08.
During the outlook period the probability of a geo-effective (Earth facing)
Coronal Mass Ejection (CME) is placed at 10%.
During the outlook period the probability of unsettled (Kp-3)
geomagnetic conditions is placed at 100%.
During the outlook period the probability of active (Kp-4)
geomagnetic conditions is placed at 70%.
During the outlook period the probability of at least a minor ionospheric
storm (Kp-5)(G1) is placed at 30%.
During the outlook period the probability of at least a moderate ionospheric
storm (Kp-6)(G2) is placed at 20%.
During the outlook period the probability of at least a strong ionospheric
storm (Kp-7+)(G3+) is placed at 10%.
G5 = Extreme - Kp = 9
G4 = Severe - Kp = 8
G3 = Strong - Kp = 7
G2 = Moderate - Kp = 6
G1 = Minor - Kp = 5
Active - Kp = 4
Unsettled - Kp = 3
During the outlook period the probability of a visible high latitude Aurora display is placed at
50%, mid latitude 20%.
On 02/12/05 at 2017 UTC the Bz is 10.1 nt north.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
the Sun's IMF polarity, forecasts a positive (+) polarity between 02/12/06-08 and
a negative (-) polarity between 02/12/09-13.
When the polarity of the IMF is negative a visible mid latitude Aurora
display is likely when a CME strikes the Earth's magnetic field. When the polarity of the IMF is
positive a visible mid latitude Aurora display is unlikely as a CME strikes the Earth's magnetic
field.
A Geomagnetic or Ionospheric Storm is a worldwide disturbance of the earth's magnestosphere induced by
the Sun's interplanetary magnetic field (IMF), distinct from regular diurnal variations.
A Coronal Mass Ejection is the name given to an ejection of a large amount
of matter from the Sun's outer atmosphere or corona. These ejections typically comprise millions of
tons of material in the form of charged particles, and can be seen because the material reflects
sunlight. When one of these ejections is directed towards the Earth (or conversely, directly away
from the Earth), it looks like a roughly circular "halo" surrounding the Sun.
The "Halo CME's" then are those CME's which are more likely to impact the
Earth than those which are shot out at right angles to the Earth-Sun line. Energetic protons
emitted during CME's play a major role in increased day time and night-time D-layer absorption of
mediumwave frequencies.
Coronal Mass Ejections were once thought to be completely initiated by solar
flares. However it is now known that many (CME's) are not associated with Solar Flares. If a (CME)
collides with the Earth, it can excite a Geomagnetic Storm if the polarity of the IMF has a
negative sign. We must be vigilant in watching for geoeffective (CME's), in order to not be caught
by surprise with a seemingly sudden and unexpected Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in
magnetic latitude and generally begins having a negative impact on high latitude medium frequency
propagation paths. A Kp index of 5 or higher begins to have a negative impact on high latitude high
frequency shortwave propagation paths. However at times skewed path propagation conditions can
compensate for high
latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the seven day outlook period increased winter like day and year round night
time D layer absorption of medium frequency signals tied to stratospheric warming in the northern
hemisphere is possible, due to a large scale movement of Arctic air across the North Pole from
Siberian Russia into Canada.
In the nearer term of 7-14 days we continue in a negative North Atlantic Oscillation (NAO) and Positive
West Negative East (PNA) upper air height anomaly pattern. This means a big ridge in the west all
the way into the Yukon region of Canada, a deep trough in the eastern U.S. down into the Yucatan
region of Mexico and another ridge in the western North Atlantic Ocean. This pattern is also called
a dual blocking ridge. This pattern taps Siberian Arctic air across the North Pole and sends it
rushing south, increasing the chances of stratospheric warming.
As the stratosphere lies below the ionosphere, which
is at mesosphere and thermosphere height, you would not expect to see
stratospheric warming effect medium frequency propagation in any way BUT
medium frequency signals do propagate off of temperature inversions
and moisture discontinuities and a temperature inversion is involved
with stratospheric warming. So it's probable that a medium frequency
signal could do any number of things when scattering off of a temperature
inversion, at any height. Unfortunately though some otherwise very knowledgeable
Physicists stubbornly resist this concept.
Also stratospheric warming (STRATWARM) has a negative effect on medium
frequency propagation, due to increasing medium frequency radio wave absorption by the D layer, via
upward propagating Internal Gravity Waves (IGW).
Also I have observed that stratospheric warming usually coincides with major
jetstream circulation pattern changes and movement of Arctic air masses from Siberian Russia across
the pole to Canada and the U.S.
This phenomenon also occurs in southern hemisphere winter but seems to be
less pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-34
Published 4:00 PM EST 02/11/24 For 02/11/25-02/12/01.
Overall medium frequency propagation conditions should improve some compared
with the previous 30 days.
Expect good domestic propagation conditions on east-west paths and fair on
north south paths in the northern hemisphere out to approximately 1050 miles.
Expect fair domestic propagation conditions on east-west paths and fair on
north south paths in the southern hemisphere out to approximately 1050 miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be fair.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be fair to good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be fair.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions
in excess of approximately 3000 miles should be good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions
in excess of approximately 3000 miles should be good.
During the outlook period there will be "moderate to high" lightning induced QRN levels in mid
latitude areas of the northern hemisphere tied to warm and cold season thunderstorms, tropical
systems, cold/warm/occluded fronts associated with extra-tropical cold core low pressure systems.
High latitude regions can expect “low to occasionally moderate” lightning induced QRN.
During the outlook period there will be "high" lightning induced QRN levels in mid latitude areas
of the southern hemisphere tied to warm season thunderstorms and tropical systems and to a lesser
extent cold/warm/occluded fronts associated with extra-tropical cold core low pressure systems.
High latitude regions can expect “low to occasionally moderate” lightning induced QRN.
High lightning induced QRN in association with year round thunderstorm activity will continue in
the vicinity of the northern and southern tropical ITCZ and across equatorial regions.
Here are some general guidelines concerning correlation of space weather and propagation indices
to actual expected MF propagation conditions.
1.) Dropping indices numbers are better.
2.) Solar flux under 150 okay, under 100 better, 70 is best for E layer multi hop.
3.) Solar flux of at least 100 for E valley-F layer ducting mechanism.
4.) Previous 24 hour Ap index under 10, under 7 for several days consecutively is best.
5.) Previous 3 hour Kp index under 3 for mid latitude paths, under 2 for high latitude paths, 0-1
for several days consecutively is best.
6.) Energetic protons no greater then 10 MeV (10+0) for 160/120 meters and no greater then (10-1)
on MF broadcast band.
7.) Background x-ray flux levels less than C2 for several days consecutively for 160/120 meters
and less then C1 for MF broadcast band.
8.) No current STRATWARM alert.
9.) IMF Bz with a negative sign, indicates a better chance of high latitude path auroral
absorption/unpredictable refraction or scattering of MF RF signals, when the Kp is above 3.
SPACE WEATHER INDICES EXPECTED DURING THE SEVEN DAY PERIOD AND EXPLANATIONS OF THEIR IMPACT
ON EXPECTED PROPAGATION CONDITIONS.
ENERGETIC PROTON FLUX-
During the three day outlook period the probability of an elevated energetic
proton flux event >10 MeV (10+0) is placed at 10%.
An elevated energetic proton flux level greater then (10+0) on 160 meters
and greater then (10-1) on the medium frequency broadcast band creates noticeably increased winter
time day and year round night time D layer absorption of medium wave frequencies, especially on
high latitude propagation paths but it can also negatively impact mid latitudes, depending on the
intensity of the event.
Elevated energetic proton events too small to be categorized as a Polar Cap
Absorption event (PCA) can still impact high and mid level medium frequency propagation paths in
the form of excessive D layer absorption. This fact is still stubbornly opposed by some otherwise
very knowledgeable space weather physicists over dependent on high latitude threshold Riometer readings.
((((Note, high latitude medium frequency radio propagation paths can still
be disturbed for days and up to weeks, following the end of an official >10 MeV (10+0) proton
event.))))
SOLAR FLUX-
During the past seven days the daily solar flux levels ranged between 193 and 147.
During the outlook period the daily solar flux values should range
between approximately 180 and 140.
Elevated background X-ray flux levels can impact propagation of medium
frequency signals in a negative manner. Background X-ray flux levels of C2 or greater creates
increased D-layer absorption of 160 and 120 meter signals and C1 or greater creates increased
D-layer absorption of AM broadcast band signals.
High solar flux values are generally considered to be detrimental to
propagation of medium frequency signals both domestic and Trans Atlantic (TA) & Trans Pacific
(TP), as more absorption can be present via the transmitted signals' two trips through the D layer
at the takeoff and arrival points.
Most "strong" longer haul medium frequency DX signals in excess of 3000
miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high
solar flux values can aid in long haul medium frequency propagation paths in excess of 3000 miles,
as a high solar flux value ensures a strong F layer part of the E Valley-F layer duct or Chordal
Hop propagation mechanism.
However high solar activity in the form of increased ionization created by
Ultraviolet and X-Ray radiation can fill in the E Valley region and interfere with the E Valley-F
layer ducting mechanism. In a sense the E Valley-F layer duct is closed on one or both ends of a
propagation path and the transmitted MF RF signal only propagates between the E layer and
land/ocean surface, with a higher angle and more loss.
SOLAR FLARES & SUNSPOT GROUP REGIONS-
During the previous 7 day period two M class solar flares
occurred. The largest was and M5.7 class solar flare which occurred
between 0204-0219 UTC on 02/11/18 and erupted from sunspot region
#10191. And HF signal fadeout occurred with this flare Australia, New Zealand
and Micronesia.
Sunspot region #10198 geo-effective position (Earth facing) at S18W25 contains a beta-gamma class
magnetic signature and harbors energy for a large M class solar flares.
Fortunately this sunspot group will be rotating around the west limb of the Sun soon.
During the three day period I place the chance of a C class solar flare at
100%, and M class solar flare at 50% and an X class solar flare at 10%.
A C4 or higher class solar flare "can" elevate the proton flux above 10 MeV (10+0) and initiate
large scale high and mid latitude propagation path absorption on the AM broadcast band, 160 and
120 meters, both stateside and DX, as a transfer of increased density and RF signal absorption
from the day side D layer to night side of the ionosphere occurs through high level neutral winds.
Unfortunately even smaller C3 solar flares can create hour to hour and night to night variations
in signal strength on medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths tend to open up after a significant period of time passes without an elevated energetic
proton event of >10 MeV (10+0). This fact is still stubbornly opposed by some otherwise very
knowledgeable space weather physicists over dependent on high latitude threshold Riometer
readings.
Openings also occur when the solar background x-ray level falls back to or
below C1 for 160 and 120 meters and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
No geo-effective (Earth facing) Coronal Mass Ejections Occurred.
During the previous seven day period a large Coronal Hole had been in a geo-effective (Earth
facing) position. It's related Solar Wind Stream impacted the Earth's (IMF), with a Kp index
varying between a 4 (active) and a 7 (major ionospheric storm) . Fortunately this coronal hole is
moving west out of geo-effective position.
During the outlook period another geo-effective (Earth facing) Coronal
Hole and related Solar Wind Stream is expected to impact the Earth's (IMF). Impact on the (IMF)
should begin on 02/11/24-25.
During the outlook period the probability of a geo-effective (Earth facing)
Coronal Mass Ejection (CME) is placed at 20%.
During the outlook period the probability of unsettled (Kp-3)
geomagnetic conditions is placed at 100%.
During the outlook period the probability of active (Kp-4)
geomagnetic conditions is placed at 80%.
During the outlook period the probability of at least a minor ionospheric
storm (Kp-5)(G1) is placed at 50%.
During the outlook period the probability of at least a moderate ionospheric
storm (Kp-6)(G2) is placed at 40%.
During the outlook period the probability of at least a strong ionospheric
storm (Kp-7+)(G3+) is placed at 30%.
G5 = Extreme - Kp = 9
G4 = Severe - Kp = 8
G3 = Strong - Kp = 7
G2 = Moderate - Kp = 6
G1 = Minor - Kp = 5
Active - Kp = 4
Unsettled - Kp = 3
During the outlook period the probability of a visible high latitude Aurora display is placed at
60%, mid latitude 30%.
At 1837 UTC on 02/11/24 the Bz is 2.1 nt south.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
Earth's IMF polarity, forecasts a negative (-) polarity during the seven day period.
When the polarity of the IMF is negative a visible mid latitude Aurora
display is likely when a CME strikes the Earth's magnetic field. When the polarity of the IMF is
positive a visible mid latitude Aurora display is unlikely as a CME strikes the Earth's magnetic
field.
A Coronal Mass Ejection is the name given to an ejection of a large amount
of matter from the Sun's outer atmosphere or corona. These ejections typically comprise millions
of tons of material in the form of charged particles, and can be seen because the material
reflects sunlight. When one of these ejections is directed towards the Earth (or conversely,
directly away from the Earth), it looks like a roughly circular "halo" surrounding the Sun.
The "Halo CME's" then are those CME's which are more likely to impact the
Earth than those which are shot out at right angles to the Earth-Sun line. Energetic protons
emitted during CME's play a major role in increased day time and night-time D-layer absorption of
mediumwave frequencies.
Coronal Mass Ejections were once thought to be completely initiated by solar
flares. However it is now known that many (CME's) are not associated with Solar Flares. If a (CME)
collides with the Earth, it can excite a Geomagnetic Storm if the polarity of the IMF has a
negative sign. We must be vigilant in watching for geoeffective (CME's), in order to not be caught
by surprise with a seemingly sudden and unexpected Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in
magnetic latitude and generally begins having a negative impact on high latitude medium frequency
propagation paths. A Kp index of 5 or higher begins to have a negative impact on high latitude
high frequency shortwave propagation paths. However at times skewed path propagation conditions
can compensate for high latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the seven day outlook period increased winter like day and year round night
time D layer absorption of medium frequency signals tied to stratospheric warming in the northern
hemisphere is possible, due to a large scale movement of Arctic air across the North Pole from
Siberian Russia into Canada.
In the nearer term of 7-14 days we are moving into a negative North Atlantic Oscillation (NAO) and
Positive West Negative East (PNA) upper air height anomaly pattern. This means a big ridge in the
west all the way into the Yukon region of Canada, a deep trough in the eastern U.S. down into the
Yucatan region of Mexico and another ridge in the western North Atlantic Ocean. This pattern is
also called a dual blocking ridge. This pattern taps Siberian Arctic air across the North Pole and
sends it rushing south, increasing the chances of stratospheric warming.
As the stratosphere lies below the ionosphere, which
is at mesosphere and thermosphere height, you would not expect to see
stratospheric warming effect medium frequency propagation in any way BUT
medium frequency signals do propagate off of temperature inversions
and moisture discontinuities and a temperature inversion is involved
with stratospheric warming. So it's probable that a medium frequency
signal could do any number of things when scattering off of a temperature
inversion, at any height. Unfortunately though some otherwise very knowledgeable
Physicists stubbornly resist this concept.
Also stratospheric warming (STRATWARM) has a negative effect on medium
frequency propagation, due to increasing medium frequency radio wave absorption by the D layer,
via upward propagating Internal Gravity Waves (IGW).
Also I have observed that stratospheric warming usually coincides with major
jetstream circulation pattern changes and movement of Arctic air masses from Siberian Russia
across the pole to Canada and the U.S.
This phenomenon also occurs in southern hemisphere winter but seems to be
less pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-33A Update
Published 4:00 PM EST 02/11/22 For 02/11/22-02/11/24.
MF propagation outlook for the CQ Worldwide CW DX Contest.
A Coronal Hole has been in a geo-effective (Earth facing) position since 02/11/18. It's
related Solar Wind Stream has and will continue to impact the Earth's (IMF) through through
the contest period. The Kp index has varied between a 4 (active) and a 7 (major ionospheric storm)
and a Kp range of 4-5 (active to minor storm) is expected during the next 48 hours.
Expect good domestic propagation conditions on east-west paths and fair on
north-south paths in the northern hemisphere out to approximately 1050 miles.
Expect good domestic propagation conditions on east-west paths and fair on
north-south paths in the southern hemisphere out to approximately 1050 miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be poor to fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be poor to fair.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be fair to good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000 miles
should be fair to good.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions
in excess of approximately 3000 miles should be good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions
in excess of approximately 3000 miles should be good.
There will be "moderate to high" lightning induced QRN levels in mid and low latitude areas of the
northern hemisphere tied to warm and cold season thunderstorms, tropical systems, cold/warm fronts
and extra-tropical low pressure systems during the forecast period.
There will be "moderate to high" lightning induced QRN levels in mid and low
latitude areas of the southern hemisphere tied to warm and cold season thunderstorms, tropical
systems, cold/warm fronts and extra-tropical low pressure systems during the forecast period.
High to moderate lightning induced QRN will continue in the vicinity of the
tropical ITCZ and across equatorial regions.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-33
Published
10:00 PM EDT 02/11/17 For 02/11/18-02/11/24.
02/11/18-02/11/24 PERIOD
OUTLOOK-
During the previous 7 day period MF propagation conditions were
poor to at
times fair on high latitude paths, fair to at times good on mid
latitude
paths and good to at times very good on low latitude
paths.
During the outlook period overall MF propagation conditions
should
be similar.
Expect good domestic propagation conditions on
east-west paths and fair on
north-south paths in the northern hemisphere out
to approximately 1050
miles.
Expect good domestic propagation
conditions on east-west paths and fair on
north-south paths in the southern
hemisphere out to approximately 1050
miles.
"High latitude"
northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross
equatorial propagation conditions in excess of approximately 3000
miles
should be poor to fair.
"High latitude" southern hemispheric (TA) Trans
Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in
excess of approximately 3000
miles should be poor to fair.
"Mid
latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and
cross equatorial propagation conditions in excess of approximately 3000
miles
should be fair to good.
"Mid latitude" southern hemisphere (TA) Trans
Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in
excess of approximately 3000
miles should be fair to good.
"Low
latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans
Pacific
propagation conditions in excess of approximately 3000 miles should
be good
to very good.
"Low latitude" southern hemisphere (TA) Trans
Atlantic, (TP) Trans Pacific
propagation conditions in excess of
approximately 3000 miles should be good
to very good.
With the
continued strengthening of the El Nino pattern in the northern
hemisphere and
it's attendant stoked up sub tropical jetstream, a higher
night to night
level of QRN can be expected with and endless number of mid
latitude storms
systems, much like the Winter of 1997-98.
There will be "moderate to
high" lightning induced QRN levels in mid and low
latitude areas of the
northern hemisphere tied to late season tropical
systems, cold/warm fronts
and extra-tropical low pressure systems during
the forecast
period.
There will be "moderate to high" lightning induced QRN levels in
mid and low
latitude areas of the southern hemisphere tied to warm season
thunderstorms
during the forecast period.
High to moderate lightning
induced QRN will continue in the vicinity of the
tropical ITCZ and across
equatorial regions.
PAST AND FUTURE SPACE WEATHER INDICES AND
EXPLANATIONS
OF THEIR IMPACT ON PROPAGATION CONDITIONS.
ENERGETIC
PROTON FLUX-
During the previous seven day period no >10 MeV (10+0)
energetic proton
event occurred.
During the new outlook period the
probability of an elevated energetic
proton flux event >10 MeV (10+0) is
placed at 50%.
An elevated energetic proton flux level greater then
(10+0) on 160 meters
and greater then (10-1) on the medium frequency
broadcast band creates
noticeably
increased winter time day and year round
night time D layer absorption of
medium wave frequencies, especially on high
latitude propagation paths but
it can also negatively impact mid latitudes,
depending on the intensity of
the event.
Elevated energetic proton
events too small to be categorized as a Polar Cap
Absorption event (PCA) can
still impact high and mid level medium frequency
propagation paths in the
form of excessive D layer absorption. This fact is
still stubbornly opposed
by some otherwise very knowledgeable space weather
physicists over dependent
on threshold Riometer readings.
Note, high latitude medium frequency
radio propagation paths can still
be disturbed for days and sometimes up to
weeks, following the end of an
official >10
MeV (10+0) proton
event.
SOLAR FLUX-
During the previous 7 day period the daily
solar flux values ranged between
204 and 167.
During the new outlook
period the daily solar flux values should range
between approximately 200 and
160.
During the previous 7 day period the background X-ray flux levels
ranged
between C1.2 and B8.3.
Elevated background X-ray flux
levels can impact propagation of medium
frequency signals in a negative
manner. Background X-ray flux levels of C2
or greater creates increased
D-layer absorption of 160 and 120 meter signals
and
C1 or greater creates
increased D-layer absorption of AM broadcast band
signals.
High solar
flux values are generally considered to be detrimental to
propagation of
medium frequency signals both domestic and Trans Atlantic
(TA) &
Trans Pacific (TP), as more absorption can be present via the
transmitted
signals' two trips through the D layer at the takeoff and
arrival
points.
Most "strong" longer haul medium frequency DX signals in excess
of 3000
miles is via the E Valley-F layer ducting and/or Chordal Hop
propagation
modes. Therefore high solar flux values can aid in long haul
medium
frequency
propagation paths in excess of 3000 miles, as a high
solar flux value
ensures a strong
F layer part of the E Valley-F layer
duct or Chordal Hop propagation
mechanism.
However high solar activity
in the form of increased ionization created by
Ultraviolet and X-Ray
radiation can fill in the E Valley region and
interfere with the E Valley-F
layer ducting mechanism. In a sense the E
Valley-F
layer duct is closed on
one or both ends of a propagation path and the
transmitted MF
RF signal
only propagates between the E layer and land/ocean surface, with a
higher
angle and more loss.
SOLAR FLARES & SUNSPOT GROUP
REGIONS-
During the previous 7 day period seven M class solar flares
occurred.
The largest was and M5.7 class solar flare which occurred
between 0204-0219
UTC on 02/11/18 and erupted from sunspot region
#10191.
Large sunspot region #10191 at S18W87 which is in gro-effective
(Earth
facing)position, contains a beta-gamma-delta magnetic signature and
harbors
energy for large M class solar flares. This group is also capable of
and
isolated huge X class solar flare. Fortunately it will rotate around
the
western limb of the Sun soon.
It's to early to tell but sunspot
region #10191 may have emitted and
excessive level of Energetic Protons and a
Coronal Mass Ejection (CME).
Sunspot region #10195 at S16E32 contains a
beta-gamma magnetic signature and
harbors energy for large M class solar
flares.
Sunspot region #10198 at S17E57 contains a beta magnetic
signature and
harbors energy for small to medium M class solar
flares.
The solar flare forecast for the outlook period is as
follows:
C class solar flare 100%,
M class solar flare at 60%,
X
class solar flare at 10%.
An earthward facing C4 or higher class
solar flare "can" elevate the proton
flux above 10 MeV (10+0) and initiate
large scale high and mid latitude
propagation path absorption on the AM
broadcast band, 160 and 120 meters,
both
stateside and DX, as a transfer
of increased density and RF signal
absorption from the
day side D layer to
night side of the ionosphere occurs through high level
neutral winds.
Unfortunately even smaller C3 solar flares can create hour to
hour and night
to night variations in signal strength on medium frequencies.
High and
mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths
tend to open up after a significant period of time passes without an
elevated
energetic proton event of >10 MeV (10+0). This fact is still
stubbornly
opposed by
some otherwise very knowledgeable space weather physicists over
dependent on
threshold Riometer readings.
Openings also occur when the
solar background x-ray level falls back to or
below C1 for 160 and 120 meters
and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC
STORMS/VISIBLE AURORA-
During the previous 7 day period no geo-effective
(Earth facing) Coronal
Mass Ejection (CME) occurred.
During the
previous 7 day period our planet also encountered a Solar Wind
Stream flowing
from a geo-effective (Earth facing) Coronal Hole. This Solar
Wind Stream
created a seven day period with repeated active conditions (Kp
of 4),
igniting high latitude visible Aurora displays.
During the new outlook
period a large geo-effective (Earth facing) Coronal
Hole will move into
geo-effective (Earth facing) position by 02/11/18. It's
related
Solar Wind
Stream is expected to impact the Earth's (IMF) by 02/11/19.
During the
outlook period the probability of a geo-effective (Earth facing)
Coronal Mass
Ejection (CME) is placed at 60%.
During the outlook period the
probability of unsettled (Kp-3) geomagnetic
conditions is placed at
100%.
During the outlook period the probability of active (Kp-4)
geomagnetic
conditions is placed at 70%.
During the outlook period the
probability of at least a minor ionospheric
storm (Kp-5)(G1) is placed at
60%.
During the outlook period the probability of at least a moderate
ionospheric
storm (Kp-6)(G2) is placed at 50%.
During the outlook
period the probability of at least a strong ionospheric
storm (Kp-7+)(G3+) is
placed at 40%.
G5 = Extreme - Kp = 9
G4 = Severe - Kp = 8
G3 =
Strong - Kp = 7
G2 = Moderate - Kp = 6
G1 = Minor - Kp = 5
    Active
- Kp = 4
    Unsettled - Kp = 3
During the outlook period the
probability of a visible mid latitude Aurora
display is placed at
70%.
At 0203 UTC on 02/11/18 the Bz is 2.8 nt south.
The
Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
Earth's
IMF polarity, forecasts a negative (-) polarity
from
02/11/18-02/11/24.
When the polarity of the IMF is negative a
visible mid latitude Aurora
display is likely when a CME strikes the Earth's
magnetic field. When the
polarity of the IMF is positive a visible mid
latitude Aurora display is
unlikely as a
CME strikes the Earth's magnetic
field.
A Coronal Mass Ejection is the name given to an ejection of a
large amount
of matter from the Sun's outer atmosphere or corona. These
ejections
typically comprise millions of tons of material in the form of
charged
particles, and
can be seen because the material reflects sunlight.
When one of these
ejections is directed towards the Earth (or conversely,
directly away from
the Earth), it looks like a roughly circular "halo"
surrounding the Sun.
The "Halo CME's" then are those CME's which are more
likely to impact the
Earth than those which are shot out at right angles to
the Earth-Sun line.
Energetic protons emitted during CME's play a major role
in increased day
time and
night-time D-layer absorption of mediumÂ
frequencies.
Coronal Mass Ejections were once thought to be completely
initiated by solar
flares. However it is now known that many (CME's) are not
associated with
Solar Flares. If a (CME) collides with the Earth, it can
excite a
Geomagnetic Storm if the polarity of the IMF has a negative sign. We
must be
vigilant in watching for geoeffective (CME's), in order to not be
caught by
surprise with a seemingly sudden and unexpected Geomagnetic
Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding
equatorward in
magnetic latitude and it generally begins having a negative
impact on high
latitude medium frequency propagation paths. A Kp index of 5
or higher
begins to have a negative impact on high latitude high frequency
shortwave
propagation paths. However at times skewed path propagation
conditions can
compensate for high latitude propagation path
auroral
absorption.
STRATOSPHERIC WARMING-
During the
outlook period increased winter like day and year round night
time D layer
absorption of medium frequency signals tied to stratospheric
warming in the
northern hemisphere is possible, due to a large scale
movement of Arctic air
across the North Pole from Siberian Russia
into
Canada.
Stratospheric warming is a major temperature change
of the winter time polar
and middle atmosphere from the tropopause (where the
troposphere transitions
into the stratosphere) to the base (D-layer) of the
ionosphere, lasting for
many days
at a time and characterized by a warming
of the stratospheric temperature by
some tens of degrees (temperature
inversion). As the stratosphere lies below
the ionosphere, which is at
mesosphere and thermosphere height, you would
not expect to see stratospheric
warming effect medium frequency propagation
in any way BUT medium frequency
signals do refract off of temperature
inversions and moisture discontinuities
and a temperature inversion is
involved with stratospheric warming. So it's
probable that a medium
frequency signal could do any number of things when
refracting off of a
temperature inversion, at any height.
Also
stratospheric warming (STRATWARM) has a negative effect on medium
frequency
propagation, due to increasing medium frequency radio wave
absorption by the
D layer, via upward propagating Internal Gravity Waves
(IGW).
Also I
have observed that stratospheric warming usually coincides with
major
jetstream circulation pattern changes and movement of Arctic air masses
from
Siberian Russia across the pole to Canada and the U.S.
This
phenomenon also occurs in southern hemisphere winter but seems to be
less
pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-32
Published
12:00 AM EDT 02/11/11 For 02/11/11-02/11/17.
02/11/11-02/11/17 PERIOD
OUTLOOK-
During the previous 7 day period MF propagation conditions were
poor on
high latitude paths, fair on mid latitude paths and good on low
latitude
paths.
However on Thursday and Friday 02/11/07-08 propagation
conditions did
improve to fair on high latitude paths, good on mid latitude
paths and very
good
on low latitude paths.
Unfortunately this short
lived good propagation period ended abruptly at
1920 UTC
on 02/11/09 with
the onset of and >10 MeV (10+0) elevated energetic
proton
event.
During the outlook period overall MF propagation
conditions should
be similarly poor as the last period, with more absorptive
geomagnetic
activity expected, with a Kp of 6-7 and a continued >10 MeV
(10+0)
energetic
proton event .
Expect good domestic propagation
conditions on east-west paths and fair on
north-south paths in the northern
hemisphere out to approximately 1050
miles.
Expect good domestic
propagation conditions on east-west paths and fair on
north-south paths in
the southern hemisphere out to approximately 1050
miles.
"High
latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and
cross equatorial propagation conditions in excess of approximately 3000
miles
should be fair.
"High latitude" southern hemispheric (TA) Trans Atlantic,
(TP) Trans Pacific
and cross equatorial propagation conditions in excess of
approximately 3000
miles should be fair.
"Mid latitude" northern
hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions in excess of approximately 3000
miles should be
fair
to good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic,
(TP) Trans Pacific
and cross equatorial propagation conditions in excess of
approximately 3000
miles should be fair
to good.
"Low latitude"
northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation
conditions in excess of approximately 3000 miles should be good.
"Low
latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans
Pacific
propagation conditions in excess of approximately 3000 miles should
be good.
With the continued strengthening of the El Nino pattern in
the northern
hemisphere and it's attendant stoked up sub tropical jetstream,
a higher
night to night level of
QRN can be expected with and endless
number of mid latitude storms systems,
much like the Winter of
1997-98.
There will be "moderate to high" lightning induced QRN levels in
mid and low
latitude areas of the northern hemisphere tied to late season
tropical
systems, cold/warm fronts and extra-tropical low pressure systems
during the
forecast period.
There will be "moderate to high" lightning
induced QRN levels in mid and low
latitude areas of the southern hemisphere
tied to warm season thunderstorms
during the forecast period.
High to
moderate lightning induced QRN will continue in the vicinity of the
tropical
ITCZ and across equatorial regions.
PAST AND FUTURE SPACE WEATHER
INDICES AND EXPLANATIONS OF THEIR IMPACT ON
PROPAGATION
CONDITIONS.
ENERGETIC PROTON FLUX-
During the previous seven day
period one >10 MeV (10+0) energetic proton
event occurred. This event was
courtesy of and M4.6 class solar flare
which occurred between 1309-1359 UTC
on 02/11/09 and erupted from sunspot
region 10180.
This elevated
energetic proton event peaked at 404 pfu at 0540 UTC on
02/11/10
and
though dropping is still occurring and should resurge upwards once
again
during the
next 24 hour period.
During the new outlook period
the probability of an elevated energetic
proton flux event >10 MeV (10+0)
is placed at 100%.
An elevated energetic proton flux level greater
then (10+0) on 160 meters
and greater then (10-1) on the medium frequency
broadcast band creates
noticeably
increased winter time day and year round
night time D layer absorption of
medium wave frequencies, especially on high
latitude propagation paths but
it can also negatively impact mid latitudes,
depending on the intensity of
the event.
Elevated energetic proton
events too small to be categorized as a Polar Cap
Absorption event (PCA) can
still impact high and mid level medium frequency
propagation paths in the
form of excessive D layer absorption. This fact is
still stubbornly opposed
by some otherwise very knowledgeable space
weather physicists over dependent
on threshold Riometer readings.
Note, high latitude medium frequency
radio propagation paths can still
be disturbed for days and sometimes up to
weeks, following the end of an
official >10
MeV (10+0) proton
event.
SOLAR FLUX-
During the previous 7 day period the daily
solar flux values ranged between
201 and 177.
During the new outlook
period the daily solar flux values should range
between approximately 200 and
180.
During the previous 7 day period the background X-ray flux levels
ranged
between C1.2 and B6.7.
Elevated background X-ray flux
levels can impact propagation of medium
frequency signals in a negative
manner. Background X-ray flux levels of C2
or greater creates increased
D-layer absorption of 160 and 120 meter signals
and
C1 or greater creates
increased D-layer absorption of AM broadcast band
signals.
High solar
flux values are generally considered to be detrimental to
propagation of
medium frequency signals both domestic and Trans Atlantic
(TA)
&
Trans Pacific (TP), as more absorption can be present via the
transmitted
signals'
two trips through the D layer at the takeoff and
arrival points.
Most "strong" longer haul medium frequency DX signals in
excess of 3000
miles is via the E Valley-F layer ducting and/or Chordal Hop
propagation
modes. Therefore high solar flux values can aid in long haul
medium
frequency
propagation paths in excess of 3000 miles, as a high
solar flux value
ensures a strong
F layer part of the E Valley-F layer
duct or Chordal Hop propagation
mechanism.
However high solar activity
in the form of increased ionization created by
Ultraviolet and X-Ray
radiation can fill in the E Valley region and
interfere with the E Valley-F
layer ducting mechanism. In a sense the E
Valley-F
layer duct is closed on
one or both ends of a propagation path and the
transmitted MF
RF signal
only propagates between the E layer and land/ocean surface, with a
higher
angle and more loss.
SOLAR FLARES & SUNSPOT GROUP
REGIONS-
During the previous 7 day period four M class solar flares
occurred.
The largest was and M4.6 class solar flare which occurred
between 1309-1359
UTC on 02/11/09 and erupted from sunspot region
10180.
Large sunspot region #10180 at S10W41 contains a
beta-gamma-delta
magnetic signature and harbors energy for large M class
solar flares.
This group is capable of and isolated huge X class solar flare.
Fortunately
it will rotate around the western limb of the Sun
shortly.
Even larger sunspot region #10191 which just rotated around the
eastern limb
of the Sun at S17E63 also contains a beta-gamma-delta magnetic
signature and
harbors
energy for large M class solar flares. This group is
capable of and isolated
huge X class solar flare. A delta magnetic structure
is probable in future
days.
The solar flare forecast for the outlook
period is as follows:
C class solar flare 100%,
M class solar flare at
60%,
X class solar flare at 10%.
An earthward facing C4 or higher
class solar flare "can" elevate the proton
flux above 10 MeV (10+0) and
initiate large scale high and mid latitude
propagation path absorption on the
AM broadcast band, 160 and 120 meters,
both
stateside and DX, as a
transfer of increased density and RF signal
absorption from the
day side D
layer to night side of the ionosphere occurs through high level
neutral
winds. Unfortunately even smaller C3 solar flares can create hour to
hour and
night to night variations in signal strength on medium frequencies.
High
and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths
tend to open up after a significant period of time passes without an
elevated
energetic proton event of >10 MeV (10+0). This fact is still
stubbornly
opposed by
some otherwise very knowledgeable space weather physicists over
dependent on
threshold Riometer readings.
Openings also occur when the
solar background x-ray level falls back to or
below C1 for 160 and 120 meters
and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC
STORMS/VISIBLE AURORA-
During the previous 7 day period one "surprise"
geo-effective (Earth facing)
Coronal
Mass Ejection (CME)
occurred.
During the previous 7 day period our planet also encountered a
long
duration Solar Wind Stream flowing from a geo-effective (Earth
facing)
Coronal Hole.
This Solar Wind Stream created a seven day period
with repeated active
conditions (Kp of 4), peaking as a minor ionospheric
storm (Kp of 5) on
02/11/10, igniting high latitude
visible Aurora
displays.
During the new outlook period a large geo-effective (Earth
facing) Coronal
Hole will move into geo-effective (Earth facing) position by
02/11/16. It's
related
Solar Wind Stream is expected to impact the Earth's
(IMF) by 02/11/17.
During the outlook period the probability of a
geo-effective (Earth facing)
Coronal Mass Ejection (CME) is placed at 100%,
with the arrival of one on
02/11/11-12.
During the outlook period the
probability of unsettled (Kp-3) geomagnetic
conditions is placed at
100%.
During the outlook period the probability of active (Kp-4)
geomagnetic
conditions is placed at 90%.
During the outlook period the
probability of at least a minor ionospheric
storm (Kp-5)(G1) is placed at
80%.
During the outlook period the probability of at least a moderate
ionospheric
storm (Kp-6)(G2) is placed at 70%.
During the outlook
period the probability of at least a strong ionospheric
storm (Kp-7+)(G3+) is
placed at 60%.
G5 = Extreme - Kp = 9
G4 = Severe - Kp = 8
G3 =
Strong - Kp = 7
G2 = Moderate - Kp = 6
G1 = Minor - Kp = 5
    Active
- Kp = 4
    Unsettled - Kp = 3
During the outlook period the
probability of a visible mid latitude Aurora
display is placed at
80%.
At 0336 UTC on 02/11/11 the Bz is 1.6 nt north.
The
Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
Earth's
IMF polarity, forecasts a negative (-) polarity
from
02/11/11-02/11/17.
When the polarity of the IMF is negative a
visible mid latitude Aurora
display is likely when a CME strikes the Earth's
magnetic field. When the
polarity of the IMF is positive a visible mid
latitude Aurora display is
unlikely as a
CME strikes the Earth's magnetic
field.
A Coronal Mass Ejection is the name given to an ejection of a
large amount
of matter from the Sun's outer atmosphere or corona. These
ejections
typically comprise millions of tons of material in the form of
charged
particles, and
can be seen because the material reflects sunlight.
When one of these
ejections is directed towards the Earth (or conversely,
directly away from
the Earth), it looks like a roughly circular "halo"
surrounding the Sun.
The "Halo CME's" then are those CME's which are more
likely to impact the
Earth than those which are shot out at right angles to
the Earth-Sun line.
Energetic protons emitted during CME's play a major role
in increased day
time and
night-time D-layer absorption of mediumÂ
frequencies.
Coronal Mass Ejections were once thought to be completely
initiated by solar
flares. However it is now known that many (CME's) are not
associated with
Solar Flares. If a (CME) collides with the Earth, it can
excite a
Geomagnetic Storm if the polarity of the IMF has a negative sign. We
must be
vigilant in watching for geoeffective (CME's), in order to not be
caught by
surprise with a seemingly sudden and unexpected Geomagnetic
Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding
equatorward in
magnetic latitude and it generally begins having a negative
impact on high
latitude medium frequency propagation paths. A Kp index of 5
or higher
begins to have a
negative impact on high latitude high frequency
shortwave propagation paths.
However at times skewed path propagation
conditions can compensate for high
latitude propagation path
auroral
absorption.
STRATOSPHERIC WARMING-
During the
outlook period increased winter like day and year round night
time D layer
absorption of medium frequency signals tied to stratospheric
warming in the
northern hemisphere is possible, due to a large scale
movement of Arctic air
across the North Pole from Siberian Russia
into
Canada.
Stratospheric warming is a major temperature change
of the winter time polar
and middle atmosphere from the tropopause (where the
troposphere transitions
into the stratosphere) to the base (D-layer) of the
ionosphere, lasting for
many days
at a time and characterized by a warming
of the stratospheric temperature by
some tens of
degrees (temperature
inversion). As the stratosphere lies below the
ionosphere, which is
at
mesosphere and thermosphere height, you would not expect to
see
stratospheric warming
effect medium frequency propagation in any way
BUT medium frequency signals
do refract off of
temperature inversions and
moisture discontinuities and a temperature
inversion is involved with
stratospheric warming. So it's probable that a
medium frequency signal could
do any number of things when refracting off of
a temperature inversion, at
any height.
Also stratospheric warming (STRATWARM) has a negative effect
on medium
frequency propagation, due to increasing medium frequency radio
wave
absorption by the D layer, via upward propagating Internal Gravity
Waves
(IGW).
Also I have observed that stratospheric warming usually
coincides with major
jetstream circulation pattern changes and movement of
Arctic air masses from
Siberian Russia across the pole to Canada and the
U.S.
This phenomenon also occurs in southern hemisphere winter but seems
to be
less pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-31
Published 5:00 PM EDT 02/11/05 For 02/11/04-02/11/10.
02/11/04-02/11/10 PERIOD OUTLOOK-
During the previous 7 day period MF propagation conditions were poor to at
times fair on high latitude paths, fair to at times good on mid latitude paths and good
on low latitude paths.
During the outlook period overall MF propagation conditions should
be similarly poor as the last period, with more absorptive geomagnetic
activity expected.
Expect good domestic propagation conditions on east-west paths and fair on
north-south paths in the northern hemisphere out to approximately 1050
miles.
Expect good domestic propagation conditions on east-west paths and fair on
north-south paths in the southern hemisphere out to approximately 1050
miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair
to good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair
to good.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in excess of approximately 3000 miles should be good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in excess of approximately 3000 miles should be good.
With the continued strengthening of the El Nino pattern in the northern
hemisphere and it's attendant stoked up sub tropical jetstream, a higher night to night level of
QRN can be expected with and endless number of mid latitude storms systems, much like the Winter
of 1997-98.
There will be "moderate to high" lightning induced QRN levels in mid and low
latitude areas of the northern hemisphere tied to late season tropical
systems, cold/warm fronts and extra-tropical low pressure systems during the forecast period.
There will be "moderate to high" lightning induced QRN levels in mid and low
latitude areas of the southern hemisphere tied to warm season thunderstorms
during the forecast period.
High to moderate lightning induced QRN will continue in the vicinity of the
tropical ITCZ and across equatorial regions.
PAST AND FUTURE SPACE WEATHER INDICES AND EXPLANATIONS OF THEIR IMPACT ON
PROPAGATION CONDITIONS.
ENERGETIC PROTON FLUX-
During the previous seven day period one >10 MeV (10+0) energetic proton
event occurred. This event was courtesy of and M7.0 class solar flare
which occurred between 1649-1734 UTC on 02/10/31.
During the new outlook period the probability of an elevated energetic
proton flux event >10 MeV (10+0) is placed at 30%.
An elevated energetic proton flux level greater then (10+0) on 160 meters
and greater then (10-1)
on the medium frequency broadcast band creates noticeably increased winter
time day and year round
night time D layer absorption of medium wave frequencies, especially on high
latitude propagation
paths but it can also negatively impact mid latitudes, depending on the
intensity of the event.
Elevated energetic proton events too small to be categorized as a Polar Cap
Absorption event (PCA)
can still impact high and mid level medium frequency propagation paths in
the form of excessive D
layer absorption. This fact is still stubbornly opposed by some otherwise
very knowledgeable space
weather physicists over dependent on threshold Riometer readings.
((((Note, high latitude medium frequency radio propagation paths can still
be disturbed for days
and sometimes up to weeks, following the end of an official >10 MeV (10+0)
proton event.))))
SOLAR FLUX-
During the month of October 2002 daily solar flux values ranged between 191 and 136. During
the previous 7 day period the daily solar flux values ranged between
176 and 155.
During the new outlook period the daily solar flux values should range
between approximately 190 and 160.
During the previous 7 day period the background X-ray flux levels ranged
between C2.3 and B6.3.
Elevated background X-ray flux levels can impact propagation of medium
frequency signals in a negative manner. Background X-ray flux levels of C2
or greater creates
increased D-layer absorption of 160 and 120 meter signals and C1 or greater
creates increased D-layer absorption of AM broadcast band signals.
High solar flux values are generally considered to be detrimental to
propagation of medium
frequency signals both domestic and Trans Atlantic (TA) & Trans Pacific
(TP), as more
absorption can be present via the transmitted signals' two trips through the
D layer at the takeoff
and arrival points.
Most "strong" longer haul medium frequency DX signals in excess of 3000
miles is via the E Valley-F layer ducting and/or Chordal Hop propagation
modes. Therefore high
solar flux values can aid in long haul medium frequency propagation paths in
excess of 3000 miles,
as a high solar flux value ensures a strong F layer part of the E Valley-F
layer duct or Chordal
Hop propagation mechanism.
However high solar activity in the form of increased ionization created by
Ultraviolet and X-Ray radiation can fill in the E Valley region and
interfere with the E Valley-F
layer ducting mechanism. In a sense the E Valley-F layer duct is closed on
one or both
ends of a propagation path and the transmitted MF RF signal only propagates
between the E layer and
land/ocean surface, with a higher angle and more loss.
SOLAR FLARES & SUNSPOT GROUP REGIONS-
During the previous 7 day period six M class solar flares occurred.
The largest was and M7.0 solar flare which occurred between 1649-1734 UTC on 02/10/31.
Large sunspot region #10180 at S10E30 contains a beta-gamma-delta
magnetic signature and harbors energy for large M class solar flares.
This group is capable of and isolated huge X class solar flare.
Large sunspot region #10177 at N16E05 contains a beta-gamma
magnetic signature and harbors energy for large M class solar flares.
During the outlook period I place the chance of a C class solar flare at
100%, and M class solar flare at 60% and an X class solar flare at 20%.
An earthward facing C4 or higher class solar flare "can" elevate the proton
flux above 10 MeV (10+0) and initiate large scale high and mid latitude
propagation path
absorption on the AM broadcast band, 160 and 120 meters, both stateside and
DX, as a transfer of
increased density and RF signal absorption from the day side D layer to
night side of the
ionosphere occurs through high level neutral winds. Unfortunately even
smaller C3 solar flares can
create hour to hour and night to night variations in signal strength on
medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths tend to open up after a significant period of time passes without an
elevated energetic
proton event of >10 MeV (10+0). This fact is still stubbornly opposed by
some otherwise very
knowledgeable space weather physicists over dependent on threshold Riometer
readings.
Openings also occur when the solar background x-ray level falls back to or
below C1 for 160 and 120 meters and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
During the previous 7 day period no geo-effective (Earth facing) Coronal
Mass Ejections (CME's) occurred.
During the previous 7 day period our planet did encounter a Solar Wind
Stream flowing from a geo-effective (Earth facing) Coronal Hole. This Solar
Wind Stream created a seven day period with active conditions (Kp of 4),
peaking as a minor ionospheric storm (Kp of 5) on 02/11/02, igniting high and
mid latitude visible Aurora displays.
During the new outlook period a large geo-effective (Earth facing) Coronal
Hole will move into geo-effective (Earth facing) position by 02/11/07. It's related
Solar Wind Stream is expected to impact the Earth's (IMF) by 02/11/08.
During the outlook period the probability of a geo-effective (Earth facing)
Coronal Mass Ejection (CME) is placed at 50%.
During the outlook period the probability of unsettled (Kp-3) geomagnetic
conditions is placed at
100%.
During the outlook period the probability of active (Kp-4) geomagnetic
conditions is placed at 70%.
During the outlook period the probability of at least a minor ionospheric
storm (Kp-5)(G1) is placed at 60%.
During the outlook period the probability of at least a moderate ionospheric
storm (Kp-6)(G2) is placed at 50%.
During the outlook period the probability of at least a strong ionospheric
storm (Kp-7+)(G3+) is placed at 40%.
G5 = Extreme - Kp = 9
G4 = Severe - Kp = 8
G3 = Strong - Kp = 7
G2 = Moderate - Kp = 6
G1 = Minor - Kp = 5
Active - Kp = 4
Unsettled - Kp = 3
During the outlook period the probability of a visible mid latitude Aurora
display is placed at 60%.
At 2147 UTC on 02/11/05 the Bz is 4.7 nt south.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
Earth's IMF polarity, forecasts a positive (+) polarity from
02/11/04-02/11/10.
When the polarity of the IMF is negative a visible mid latitude Aurora
display is likely when a CME strikes the Earth's magnetic field. When the
polarity of the IMF is
positive a visible mid latitude Aurora display is unlikely as a CME strikes
the Earth's magnetic
field.
A Coronal Mass Ejection is the name given to an ejection of a large amount
of matter from the Sun's outer atmosphere or corona. These ejections
typically comprise millions of
tons of material in the form of charged particles, and can be seen because
the material reflects
sunlight. When one of these ejections is directed towards the Earth (or
conversely, directly
away from the Earth), it looks like a roughly circular "halo" surrounding
the Sun.
The "Halo CME's" then are those CME's which are more likely to impact the
Earth than those which are shot out at right angles to the Earth-Sun line.
Energetic protons
emitted during CME's play a major role in increased day time and night-time
D-layer absorption of
mediumwave frequencies.
Coronal Mass Ejections were once thought to be completely initiated by solar
flares. However it is now known that many (CME's) are not associated with
Solar Flares. If a (CME)
collides with the Earth, it can excite a Geomagnetic Storm if the polarity
of the IMF has a
negative sign. We must be vigilant in watching for geoeffective (CME's), in
order to not be caught
by surprise with a seemingly sudden and unexpected Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in
magnetic latitude and it generally begins having a negative impact on high
latitude medium
frequency propagation paths. A Kp index of 5 or higher begins to have a
negative impact on high
latitude high frequency shortwave propagation paths. However at times skewed
path propagation
conditions can compensate for high latitude propagation path auroral
absorption.
STRATOSPHERIC WARMING-
During the outlook period increased winter like day and year round night
time D layer absorption of
medium frequency signals tied to stratospheric warming in the northern
hemisphere is possible, due
to a large scale movement of Arctic air across the North Pole from Siberian
Russia into Canada.
Stratospheric warming is a major temperature change of the winter time polar
and middle atmosphere from the tropopause (where the troposphere transitions
into the
stratosphere) to the base (D-layer) of the ionosphere, lasting for many days
at a time and
characterized by a warming of the stratospheric temperature by some tens of
degrees (temperature
inversion). As the stratosphere lies below the ionosphere, which is at
mesosphere and
thermosphere height, you would not expect to see stratospheric warming
effect medium frequency
propagation in any way BUT medium frequency signals do refract off of
temperature inversions and
moisture discontinuities and a temperature inversion is involved with
stratospheric warming. So
it's probable that a medium frequency signal could do any number of things
when refracting off of a
temperature inversion, at any height.
Also stratospheric warming (STRATWARM) has a negative effect on medium
frequency propagation, due
to increasing medium frequency radio wave absorption by the D layer, via
upward propagating
Internal Gravity Waves (IGW).
Also I have observed that stratospheric warming usually coincides with major
jetstream circulation pattern changes and movement of Arctic air masses from
Siberian Russia
across the pole to Canada and the U.S.
This phenomenon also occurs in southern hemisphere winter but seems to be
less pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-30
Published
4:00 PM EDT 02/10/27 For 02/10/28-02/11/03.
02/10/28-02/11/03 PERIOD
OUTLOOK-
During the previous 7 day period MF propagation conditions were
poor to at
times fair
on high latitude paths, fair to at times good on mid
latitude paths and good
on low latitude
paths.
During the outlook
period overall MF propagation conditions should
be similarly poor as the last
period, with more absorptive geomagnetic
activity expected.
Expect
good domestic propagation conditions on east-west paths and fair
on
north-south paths in the northern hemisphere out to approximately
1050
miles.
Expect good domestic propagation conditions on east-west
paths and fair on
north-south paths in the southern hemisphere out to
approximately 1050
miles.
"High latitude" northern hemispheric
(TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation
conditions in excess of approximately 3000
miles should be fair.
"High
latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and
cross equatorial propagation conditions in excess of approximately 3000
miles
should be fair.
"Mid latitude" northern hemisphere (TA) Trans
Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in
excess of approximately 3000
miles should be fair
to good.
"Mid
latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and
cross equatorial propagation conditions in excess of approximately 3000
miles
should be fair
to good.
"Low latitude" northern hemisphere (TA)
Trans Atlantic, (TP) Trans Pacific
propagation conditions in excess of
approximately 3000 miles should be good.
"Low latitude" southern
hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in
excess of approximately 3000 miles should be good.
With the continued
strengthening of the El Nino pattern in the northern
hemisphere and
it's
attendant stoked up sub tropical jetstream, a higher night to night
level of
QRN can be expected
with and endless number of mid latitude
storms systems, much like the Winter
of 1997-98.
There will be
"moderate to high" lightning induced QRN levels in mid and low
latitude areas
of the northern hemisphere tied to late season tropical
systems, cold/warm
fronts
and extra-tropical low pressure systems during the forecast
period.
There will be "moderate to high" lightning induced QRN levels in
mid and low
latitude areas of the southern hemisphere tied to warm season
thunderstorms
during the forecast period.
High to moderate lightning
induced QRN will continue in the vicinity of the
tropical ITCZ and across
equatorial regions.
PAST AND FUTURE SPACE WEATHER INDICES AND
EXPLANATIONS OF THEIR IMPACT ON
PROPAGATION
CONDITIONS.
ENERGETIC PROTON FLUX-
During the previous
seven day period no >10 MeV (10+0) energetic proton
event
occurred.
During the new outlook period the probability of an elevated
energetic
proton flux event >10 MeV (10+0) is placed at 20%.
An
elevated energetic proton flux level greater then (10+0) on 160 meters
and
greater then (10-1)
on the medium frequency broadcast band creates noticeably
increased winter
time day and year round
night time D layer absorption of
medium wave frequencies, especially on high
latitude propagation
paths but
it can also negatively impact mid latitudes, depending on the
intensity of
the event.
Elevated energetic proton events too small to be categorized
as a Polar Cap
Absorption event (PCA)
can still impact high and mid level
medium frequency propagation paths in
the form of excessive D
layer
absorption. This fact is still stubbornly opposed by some otherwise
very
knowledgeable space
weather physicists over dependent on threshold Riometer
readings.
((((Note, high latitude medium frequency radio propagation
paths can still
be disturbed for days
and sometimes up to weeks, following
the end of an official >10 MeV (10+0)
proton
event.))))
SOLAR FLUX-
During the previous 7 day period
the daily solar flux values ranged between
189 and 156.
During the new
outlook period the daily solar flux values should range
between approximately
180 and 140.
NOTICE!!! During the outlook period F2 layer propagation
openings on 6
meters are improbable. Occasional auroral propagation is
probable, with
Sporadic E (Es) and Trans Equatorial Scatter (TEQ) openings
also probable.
During the previous 7 day period the background X-ray flux
levels ranged
between C1.2 and B4.8.
Elevated background X-ray
flux levels can impact propagation of medium
frequency signals in a negative
manner. Background X-ray flux levels of C2
or greater creates
increased
D-layer absorption of 160 and 120 meter signals and C1 or greater
creates
increased
D-layer absorption of AM broadcast band signals.
High
solar flux values are generally considered to be detrimental to
propagation
of medium
frequency signals both domestic and Trans Atlantic (TA) &
Trans Pacific
(TP), as more
absorption can be present via the transmitted
signals' two trips through the
D layer at the takeoff
and arrival
points.
Most "strong" longer haul medium frequency DX signals in excess
of 3000
miles is via the E Valley-F layer ducting and/or Chordal Hop
propagation
modes. Therefore high
solar flux values can aid in long haul
medium frequency propagation paths in
excess of 3000 miles,
as a high
solar flux value ensures a strong F layer part of the E Valley-F
layer duct
or Chordal
Hop propagation mechanism.
However high solar activity in
the form of increased ionization created by
Ultraviolet and X-Ray radiation
can fill in the E Valley region and
interfere with the E Valley-F
layer
ducting mechanism. In a sense the E Valley-F layer duct is closed on
one or
both
ends of a propagation path and the transmitted MF RF signal only
propagates
between the E layer and
land/ocean surface, with a higher angle
and more loss.
SOLAR FLARES & SUNSPOT GROUP
REGIONS-
During the previous 7 day period two M class solar flares
occurred.
The largest was and M1.5 which occurred between 1734-1819 UTC
on 02/10/25.
Very large sunspot region #10162 at N26W27 contains a
beta-gamma
magnetic signature and harbors energy for large M class solar
flares.
This group did grow larger and more complex in previous days and was
a
threat for huge X class
solar flares. And isolated huge X class solar
flare is still possible but
the group will
continue to weaken and rotate
around the western limb of the Sun shortly.
During the outlook period I
place the chance of a C class solar flare at
100%, and M class solar flare at
50% and an X class solar flare at 20%.
An earthward facing C4 or
higher class solar flare "can" elevate the proton
flux above 10 MeV (10+0)
and initiate large scale high and mid latitude
propagation path
absorption
on the AM broadcast band, 160 and 120 meters, both stateside and
DX, as a
transfer of
increased density and RF signal absorption from the day side D
layer to
night side of the
ionosphere occurs through high level neutral
winds. Unfortunately even
smaller C3 solar flares can
create hour to hour
and night to night variations in signal strength on
medium
frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific
(TP) propagation
paths tend to open up after a significant period of time
passes without an
elevated energetic
proton event of >10 MeV (10+0).
This fact is still stubbornly opposed by
some otherwise very
knowledgeable
space weather physicists over dependent on threshold
Riometer
readings.
Openings also occur when the solar background x-ray
level falls back to or
below C1 for 160 and 120 meters and B9 for the AM
broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE
AURORA-
During the previous 7 day period one geo-effective (Earth facing)
Coronal
Mass Ejection (CME)
occurred. A giant magnetic loop filled with
glowing-hot gas blasted away
from the Sun on 02/10/25.
This Eruptive
Prominence hurled a Coronal Mass Ejection (CME) toward Earth.
Quite a
large number of non geo-effective Coronal Mass Ejections (CME's)
also
occurred around the
Sun's eastern limb. As the associated sunspot region
group (10151-2?)
rotates around the eastern
limb by 02/11/01-02, more
geo-effective (Earth facing) Coronal Mass
Ejection's (CME's) are likely
to
occur.
During the previous 7 day period our planet did encounter a Solar
Wind
Stream flowing from a geo-effective (Earth facing) Coronal Hole. This
Solar
Wind Stream created a
four day ionospheric storm between
02/10/24-27, with the Kp ranging between
4 (active) and 6 (moderate storm)
and ignited high and mid latitude visible
Aurora displays.
During the
new outlook period a large geo-effective (Earth facing) Coronal
Hole and
related Solar Wind Stream is expected to "continue" to impact the
Earth's
(IMF),
however at a diminishing level.
Also a new but small coronal
hole has formed in the southeast quadrant near
the Sun's equator and
could
rotate into (Earth facing) geo-effective position on 02/10/27.
During the
outlook period the probability of a geo-effective (Earth facing)
Coronal Mass
Ejection (CME) is placed at 50%.
During the outlook period the
probability of unsettled (Kp-3) geomagnetic
conditions is placed
at
100%.
During the outlook period the probability of active (Kp-4)
geomagnetic
conditions is placed at 70%.
During the outlook period the
probability of at least a minor ionospheric
storm (Kp-5)(G1) is placed at
60%.
During the outlook period the probability of at least a moderate
ionospheric
storm (Kp-6)(G2) is placed at 50%.
During the outlook
period the probability of at least a strong ionospheric
storm (Kp-7+)(G3+) is
placed at 40%.
G5 = Extreme - Kp = 9
G4 = Severe - Kp = 8
G3 =
Strong - Kp = 7
G2 = Moderate - Kp = 6
G1 = Minor - Kp = 5
    Active
- Kp = 4
    Unsettled - Kp = 3
During the outlook period the
probability of a visible mid latitude Aurora
display is placed at
50%.
At 1926 UTC on 02/10/27 the Bz is 2.2 nt south.
The
Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
Earth's
IMF polarity, forecasts a positive (+) polarity
from
02/10/28-02/11/03.
When the polarity of the IMF is negative a
visible mid latitude Aurora
display is likely when a CME strikes the Earth's
magnetic field. When the
polarity of the IMF is
positive a visible mid
latitude Aurora display is unlikely as a CME strikes
the Earth's
magnetic
field.
A Coronal Mass Ejection is the name given to an
ejection of a large amount
of matter from the Sun's outer atmosphere or
corona. These ejections
typically comprise millions of
tons of material in
the form of charged particles, and can be seen because
the material
reflects
sunlight. When one of these ejections is directed towards the Earth
(or
conversely, directly
away from the Earth), it looks like a roughly
circular "halo" surrounding
the Sun.
The "Halo CME's" then are those
CME's which are more likely to impact the
Earth than those which are shot out
at right angles to the Earth-Sun line.
Energetic protons
emitted during
CME's play a major role in increased day time and night-time
D-layer
absorption of
mediumwave frequencies.
Coronal Mass Ejections were once
thought to be completely initiated by solar
flares. However it is now known
that many (CME's) are not associated with
Solar Flares. If a
(CME)
collides with the Earth, it can excite a Geomagnetic Storm if the
polarity
of the IMF has a
negative sign. We must be vigilant in watching
for geoeffective (CME's), in
order to not be caught
by surprise with a
seemingly sudden and unexpected Geomagnetic Storm.
As the Kp index
reaches 3-4, the aurora oval begins expanding equatorward in
magnetic
latitude and it generally begins having a negative impact on high
latitude
medium
frequency propagation paths. A Kp index of 5 or higher begins to have
a
negative impact on high
latitude high frequency shortwave propagation
paths. However at times skewed
path propagation
conditions can compensate
for high latitude propagation path
auroral
absorption.
STRATOSPHERIC WARMING-
During the
outlook period increased winter like day and year round night
time D layer
absorption of
medium frequency signals tied to stratospheric warming in the
northern
hemisphere is possible, due
to a large scale movement of Arctic
air across the North Pole from Siberian
Russia into
Canada.
Stratospheric warming is a major temperature change of the
winter time polar
and middle atmosphere from the tropopause (where the
troposphere transitions
into the
stratosphere) to the base (D-layer) of
the ionosphere, lasting for many days
at a time and
characterized by a
warming of the stratospheric temperature by some tens of
degrees
(temperature
inversion). As the stratosphere lies below the ionosphere, which
is at
mesosphere and
thermosphere height, you would not expect to see
stratospheric warming
effect medium frequency
propagation in any way BUT
medium frequency signals do refract off of
temperature inversions
and
moisture discontinuities and a temperature inversion is involved
with
stratospheric warming. So
it's probable that a medium frequency
signal could do any number of things
when refracting off of a
temperature
inversion, at any height.
Also stratospheric warming (STRATWARM) has a
negative effect on medium
frequency propagation, due
to increasing medium
frequency radio wave absorption by the D layer, via
upward
propagating
Internal Gravity Waves (IGW).
Also I have observed that
stratospheric warming usually coincides with major
jetstream circulation
pattern changes and movement of Arctic air masses from
Siberian
Russia
across the pole to Canada and the U.S.
This phenomenon also
occurs in southern hemisphere winter but seems to be
less
pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-29A Update
Published 2:00 PM EDT 02/10/24 For 02/10/25-02/10/27.
MF Propagation outlook for CQ Worldwide DX Contest, SSB: 0000Z, Oct 26 to
2400Z, Oct 27
Expect good domestic propagation conditions on east-west paths and fair on
north-south paths in the northern hemisphere out to approximately 1050
miles.
Expect good domestic propagation conditions on east-west paths and fair on
north-south paths in the southern hemisphere out to approximately 1050
miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair
to good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in excess of approximately 3000
miles should be fair
to good.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions
in excess of approximately 3000 miles should be good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions
in excess of approximately 3000 miles should be good.
There will be "moderate to high" lightning induced QRN levels in mid and low
latitude areas of the
northern hemisphere tied to warm and cold season thunderstorms, tropical
systems, cold/warm fronts
and extra-tropical low pressure systems during the forecast period.
There will be "moderate to high" lightning induced QRN levels in mid and low
latitude areas of the southern hemisphere tied to warm and cold season
thunderstorms, tropical
systems, cold/warm fronts and extra-tropical low pressure systems during the
forecast period.
High to moderate lightning induced QRN will continue in the vicinity of the
tropical ITCZ and across equatorial regions.
SPACE WEATHER INDICES EXPECTED DURING THE THREE DAY CONTEST PERIOD
AND EXPLANATIONS OF THEIR IMPACT ON PROPAGATION CONDITIONS.
ENERGETIC PROTON FLUX-
During the three day outlook period the probability of an elevated energetic
proton flux event >10 MeV (10+0) is placed at 30%.
An elevated energetic proton flux level greater then (10+0) on 160 meters
and greater then (10-1)
on the medium frequency broadcast band creates noticeably increased winter
time day and year round
night time D layer absorption of medium wave frequencies, especially on high
latitude propagation
paths but it can also negatively impact mid latitudes, depending on the
intensity of the event.
Elevated energetic proton events too small to be categorized as a Polar Cap
Absorption event (PCA)
can still impact high and mid level medium frequency propagation paths in
the form of excessive D
layer absorption. This fact is still stubbornly opposed by some otherwise
very knowledgeable space
weather physicists over dependent on threshold Riometer readings.
((((Note, high latitude medium frequency radio propagation paths can still
be disturbed for days
and up to weeks, following the end of an official >10 MeV (10+0) proton
event.))))
SOLAR FLUX-
During the three day outlook period the daily solar flux values should range
between approximately 165 and 155.
Elevated background X-ray flux levels can impact propagation of medium
frequency signals in a
negative manner. Background X-ray flux levels of C2 or greater creates
increased D-layer absorption
of 160 and 120 meter signals and C1 or greater creates increased D-layer
absorption of AM broadcast
band signals.
High solar flux values are generally considered to be detrimental to
propagation of medium
frequency signals both domestic and Trans Atlantic (TA) & Trans Pacific
(TP), as more
absorption can be present via the transmitted signals' two trips through the
D layer at the takeoff
and arrival points.
Most "strong" longer haul medium frequency DX signals in excess of 3000
miles is via the E Valley-F
layer ducting and/or Chordal Hop propagation modes. Therefore high solar
flux values can aid in
long haul medium frequency propagation paths in excess of 3000 miles, as a
high solar flux value
ensures a strong F layer part of the E Valley-F layer duct or Chordal Hop
propagation mechanism.
However high solar activity in the form of increased ionization created by
Ultraviolet and X-Ray
radiation can fill in the E Valley region and interfere with the E Valley-F
layer ducting
mechanism. In a sense the E Valley-F layer duct is closed on one or both
ends of a propagation path
and the transmitted MF RF signal only propagates between the E layer and
land/ocean surface, with a
higher angle and more loss.
SOLAR FLARES & SUNSPOT GROUP REGIONS-
Huge sunspot region #10162 at N26E10 contains a beta-gamma-delta class
magnetic signature and
harbors energy for huge large M class solar flares and isolated X class
solar flares.
During the three day period I place the chance of a C class solar flare at
100%, and M class solar flare at 60% and an X class solar flare at 30%.
An earthward facing C4 or higher class solar flare "can" elevate the proton
flux above 10 MeV
(10+0) and initiate large scale high and mid latitude propagation path
absorption on the AM
broadcast band, 160 and 120 meters, both stateside and DX, as a transfer of
increased density and RF signal absorption from the day side D layer to
night side of the
ionosphere occurs through high
level neutral winds. Unfortunately even smaller C3 solar flares can create
hour to hour and night to
night variations in signal strength on medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths tend to open up
after a significant period of time passes without an elevated energetic
proton event of >10 MeV
(10+0). This fact is still stubbornly opposed by some otherwise very
knowledgeable space weather
physicists over dependent on threshold Riometer readings.
Openings also occur when the solar background x-ray level falls back to or
below C1 for 160 and 120
meters and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
During the three day outlook period a large geo-effective (Earth facing)
Coronal
Hole and related Solar Wind Stream is expected to continue to impact the
Earth's (IMF).
During the outlook period the probability of a geo-effective (Earth facing)
Coronal Mass Ejection (CME) is placed at 30%.
During the outlook period the probability of unsettled to active (Kp-3/4)
geomagnetic conditions is placed at 100%.
During the outlook period the probability of at least a minor ionospheric
storm (Kp-5)(G1) is placed at 70%.
During the outlook period the probability of at least a moderate ionospheric
storm (Kp-6)(G2) is placed at 60%.
During the outlook period the probability of at least a strong ionospheric
storm (Kp-7+)(G3+) is placed at 50%.
G5 = Extreme - Kp = 9
G4 = Severe - Kp = 8
G3 = Strong - Kp = 7
G2 = Moderate - Kp = 6
G1 = Minor - Kp = 5
Active - Kp = 4
Unsettled - Kp = 3
During the outlook period the probability of a visible mid latitude Aurora
display is placed at 60%.
At 1627 UTC on 02/10/25 the Bz is 5.9 nt south.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
Earth's IMF polarity, forecasts a negative (-) polarity during the three day
period.
When the polarity of the IMF is negative a visible mid latitude Aurora
display is likely when a CME
strikes the Earth's magnetic field. When the polarity of the IMF is positive
a visible mid latitude
Aurora display is unlikely as a CME strikes the Earth's magnetic field.
A Coronal Mass Ejection is the name given to an ejection of a large amount
of matter from the Sun's
outer atmosphere or corona. These ejections typically comprise millions of
tons of material in the
form of charged particles, and can be seen because the material reflects
sunlight. When one
of these ejections is directed towards the Earth (or conversely, directly
away from the Earth), it
looks like a roughly circular "halo" surrounding the Sun.
The "Halo CME's" then are those CME's which are more likely to impact the
Earth than those which
are shot out at right angles to the Earth-Sun line. Energetic protons
emitted during CME's play a
major role in increased day time and night-time D-layer absorption of
mediumwave frequencies.
Coronal Mass Ejections were once thought to be completely initiated by solar
flares. However it is
now known that many (CME's) are not associated with Solar Flares. If a (CME)
collides with the
Earth, it can excite a Geomagnetic Storm if the polarity of the IMF has a
negative sign. We must be
vigilant in watching for geoeffective (CME's), in order to not be caught by
surprise with a
seemingly sudden and unexpected Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in
magnetic latitude and
generally begins having a negative impact on high latitude medium frequency
propagation paths. A Kp
index of 5 or higher begins to have a negative impact on high latitude high
frequency shortwave
propagation paths. However at times skewed path propagation conditions can
compensate for high
latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the three day outlook period increased winter like day and year round
night
time D layer absorption of
medium frequency signals tied to stratospheric warming in the northern
hemisphere is possible, due to a large scale movement of Arctic air across
the North Pole from
Siberian Russia into Canada.
Stratospheric warming is a major temperature change of the winter time polar
and middle atmosphere
from the tropopause (where the troposphere transitions into the
stratosphere) to the base (D-layer)
of the ionosphere, lasting for many days at a time and characterized by a
warming of the
stratospheric temperature by some tens of degrees (temperature inversion).
As the stratosphere lies below the ionosphere, which is at mesosphere and
thermosphere height, you
would not expect to see stratospheric warming effect medium frequency
propagation in any way BUT
medium frequency signals do refract off of temperature inversions and
moisture discontinuities and
a temperature inversion is involved with stratospheric warming. So it's
possible that a medium
frequency signal could do any number of things when refracting off of a
temperature inversion, at
any height.
Also stratospheric warming (STRATWARM) has a negative effect on medium
frequency propagation, due
to increasing medium frequency radio wave absorption by the D layer, via
upward propagating
Internal Gravity Waves (IGW).
Also I have observed that stratospheric warming usually coincides with major
jetstream circulation
pattern changes and movement of Arctic air masses from Siberian Russia
across the pole to Canada
and the U.S.
This phenomenon also occurs in southern hemisphere winter but seems to be
less pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-29
Published 2:00 PM EDT 02/10/20 For 02/10/21-02/10/27.
02/10/14-02/10/20 PERIOD OUTLOOK-
During the previous 7 day period MF propagation conditions were poor to fair
on
high latitude paths, fair to good on mid latitude paths and good to very
good on low
latitude paths.
During the outlook period overall MF propagation conditions should
be similar as the last period, as more absorptive geomagnetic activity is
expected.
Expect good domestic propagation conditions on east-west paths and fair on
north-south paths in
the northern hemisphere out to approximately 1050 miles.
Expect good domestic propagation conditions on east-west paths and fair on
north-south paths in the
southern hemisphere out to approximately 1050 miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions in excess of approximately 3000 miles should be fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions in excess of approximately 3000 miles should be fair.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions in excess of approximately 3000 miles should be fair
to good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions in excess of approximately 3000 miles should be fair
to good.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions
in excess of approximately 3000 miles should be good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions
in excess of approximately 3000 miles should be good.
There will be "moderate to high" lightning induced QRN levels in mid and low
latitude areas of the
northern hemisphere tied to warm and cold season thunderstorms, tropical
systems, cold/warm fronts
and extra-tropical low pressure systems during the forecast period.
There will be "moderate to high" lightning induced QRN levels in mid and low
latitude areas of the
southern hemisphere tied to warm and cold season thunderstorms, tropical
systems, cold/warm fronts
and extra-tropical low pressure systems during the forecast period.
High to moderate lightning induced QRN will continue in the vicinity of the
tropical ITCZ and
across equatorial regions.
PAST AND FUTURE SPACE WEATHER INDICES AND EXPLANATIONS OF THEIR IMPACT ON
PROPAGATION CONDITIONS.
ENERGETIC PROTON FLUX-
During the previous seven day period no >10 MeV (10+0) energetic proton
event occurred.
During the new outlook period the probability of an elevated energetic
proton flux event >10 MeV (10+0) is placed at 30%.
An elevated energetic proton flux level greater then (10+0) on 160 meters
and greater then (10-1)
on the medium frequency broadcast band creates noticeably increased winter
time day and year round
night time D layer absorption of medium wave frequencies, especially on high
latitude propagation
paths but it can also negatively impact mid latitudes, depending on the
intensity of the event.
Elevated energetic proton events too small to be categorized as a Polar Cap
Absorption event (PCA)
can still impact high and mid level medium frequency propagation paths in
the form of excessive D
layer absorption. This fact is still stubbornly opposed by some otherwise
very knowledgeable space
weather physicists over dependent on threshold Riometer readings.
((((Note, high latitude medium frequency radio propagation paths can still
be disturbed for days
and up to weeks, following the end of an official >10 MeV (10+0) proton
event.))))
SOLAR FLUX-
During the previous 7 day period the daily solar flux values ranged between
191 and 171.
During the new outlook period the daily solar flux values should range
between approximately 180 and 140.
NOTICE!!! During the outlook period F2 layer propagation openings on 6
meters are improbable. Occasional auroral propagation is probable, with
Sporadic E (Es) and Trans
Equatorial Scatter (TEQ) openings also probable.
During the previous 7 day period the background X-ray flux levels ranged
between M1.0 and B6.2.
Elevated background X-ray flux levels can impact propagation of medium
frequency signals in a
negative manner. Background X-ray flux levels of C2 or greater creates
increased D-layer absorption
of 160 and 120 meter signals and C1 or greater creates increased D-layer
absorption of AM broadcast
band signals.
High solar flux values are generally considered to be detrimental to
propagation of medium
frequency signals both domestic and Trans Atlantic (TA) & Trans Pacific
(TP), as more
absorption can be present via the transmitted signals' two trips through the
D layer at the takeoff
and arrival points.
Most "strong" longer haul medium frequency DX signals in excess of 3000
miles is via the E Valley-F
layer ducting and/or Chordal Hop propagation modes. Therefore high solar
flux values can aid in
long haul medium frequency propagation paths in excess of 3000 miles, as a
high solar flux value
ensures a strong F layer part of the E Valley-F layer duct or Chordal Hop
propagation mechanism.
However high solar activity in the form of increased ionization created by
Ultraviolet and X-Ray
radiation can fill in the E Valley region and interfere with the E Valley-F
layer ducting
mechanism. In a sense the E Valley-F layer duct is closed on one or both
ends of a propagation path
and the transmitted MF RF signal only propagates between the E layer and
land/ocean surface, with a
higher angle and more loss.
SOLAR FLARES & SUNSPOT GROUP REGIONS-
During the previous 7 day period four M class solar flares occurred.
The largest was and M1.8 which occurred between 0039-0119 UTC on 02/10/20.
Recently emerged and very large sunspot region #10162 at N26E59 contains a
beta-gamma-delta class
magnetic signature and harbors energy for huge large M class solar flares
and isolated X class
solar flares. This group promises to grow larger and more complex in future
days with better
chances of releasing huge X class solar flares.
Solar region #'s 10160 at S22W12, 10158 at S07W18 and 10149 at N14W62
contain a beta-gamma class
magnetic signature and harbor energy for large M class solar flares.
Solar region #'s 10149 and 10158 are in geo-effective (Earth facing)
position to hurls future CME's
at our IMF.
Fortunately though solar region #10149 will rotate across the western limb
of the Sun shortly.
During the outlook period I place the chance of a C class solar flare at
100%, and M class solar
flare at 60% and an X class solar flare at 20% early in the period and 40%
late in the period.
An earthward facing C4 or higher class solar flare "can" elevate the proton
flux above 10 MeV
(10+0) and initiate large scale high and mid latitude propagation path
absorption on the AM
broadcast band, 160 and 120 meters, both stateside and DX, as a transfer of
increased density and RF signal absorption from the day side D layer to
night side of the
ionosphere occurs through high
level neutral winds. Unfortunately even smaller C3 solar flares can create
hour to hour and night to
night variations in signal strength on medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths tend to open up
after a significant period of time passes without an elevated energetic
proton event of >10 MeV
(10+0). This fact is still stubbornly opposed by some otherwise very
knowledgeable space weather
physicists over dependent on threshold Riometer readings.
Openings also occur when the solar background x-ray level falls back to or
below C1 for 160 and 120
meters and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
During the previous 7 day period no geo-effective (Earth facing) Coronal
Mass Ejections (CME) occurred.
During the previous 7 day period our planet did encounter a Solar Wind
Stream flowing from a
geo-effective (Earth facing) coronal hole. This solar wind stream created a
four day ionospheric storm between 02/10/14-17, with the Kp ranging between
4 (active) and 6
(moderate storm) and ignited high and mid latitude visible Aurora displays.
During the new outlook period a large geo-effective (Earth facing) Coronal
Hole
and related Solar Wind Stream is expected to impact the Earth's (IMF)
beginning on 02/10/25-27.
During the outlook period the probability of a geo-effective (Earth facing)
Coronal Mass Ejection (CME) is placed at 30%.
During the outlook period the probability of unsettled to active (Kp-3/4)
geomagnetic conditions
is placed at 100%.
During the outlook period the probability of at least a minor ionospheric
storm (Kp-5)(G1) is placed at 60%.
During the outlook period the probability of at least a moderate ionospheric
storm (Kp-6)(G2) is placed at 50%.
During the outlook period the probability of at least a strong ionospheric
storm (Kp-7+)(G3+) is placed at 40%.
G5 = Extreme - Kp = 9
G4 = Severe - Kp = 8
G3 = Strong - Kp = 7
G2 = Moderate - Kp = 6
G1 = Minor - Kp = 5
Active - Kp = 4
Unsettled - Kp = 3
During the outlook period the probability of a visible mid latitude Aurora
display is placed at 50%.
At 1547 UTC on 02/10/20 the Bz is 3.8 nt north.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
Earth's IMF polarity, forecasts a negative (-) polarity from
02/10/21-02/10/27.
When the polarity of the IMF is negative a visible mid latitude Aurora
display is likely when a CME
strikes the Earth's magnetic field. When the polarity of the IMF is positive
a visible mid latitude
Aurora display is unlikely as a CME strikes the Earth's magnetic field.
A Coronal Mass Ejection is the name given to an ejection of a large amount
of matter from the Sun's
outer atmosphere or corona. These ejections typically comprise millions of
tons of material in the
form of charged particles, and can be seen because the material reflects
sunlight. When one
of these ejections is directed towards the Earth (or conversely, directly
away from the Earth), it
looks like a roughly circular "halo" surrounding the Sun.
The "Halo CME's" then are those CME's which are more likely to impact the
Earth than those which
are shot out at right angles to the Earth-Sun line. Energetic protons
emitted during CME's play a
major role in increased day time and night-time D-layer absorption of
mediumwave frequencies.
Coronal Mass Ejections were once thought to be completely initiated by solar
flares. However it is
now known that many (CME's) are not associated with Solar Flares. If a (CME)
collides with the
Earth, it can excite a Geomagnetic Storm if the polarity of the IMF has a
negative sign. We must be
vigilant in watching for geoeffective (CME's), in order to not be caught by
surprise with a
seemingly sudden and unexpected Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in
magnetic latitude and
generally begins having a negative impact on high latitude medium frequency
propagation paths. A Kp
index of 5 or higher begins to have a negative impact on high latitude high
frequency shortwave
propagation paths. However at times skewed path propagation conditions can
compensate for high
latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period increased winter like day and year round night
time D layer absorption of
medium frequency signals tied to stratospheric warming in the northern
hemisphere is possible, due to a large scale movement of Arctic air across
the North Pole from
Siberian Russia into Canada.
Stratospheric warming is a major temperature change of the winter time polar
and middle atmosphere
from the tropopause (where the troposphere transitions into the
stratosphere) to the base (D-layer)
of the ionosphere, lasting for many days at a time and characterized by a
warming of the
stratospheric temperature by some tens of degrees (temperature inversion).
As the stratosphere lies below the ionosphere, which is at mesosphere and
thermosphere height, you
would not expect to see stratospheric warming effect medium frequency
propagation in any way BUT
medium frequency signals do refract off of temperature inversions and
moisture discontinuities and
a temperature inversion is involved with stratospheric warming. So it's
possible that a medium
frequency signal could do any number of things when refracting off of a
temperature inversion, at
any height.
Also stratospheric warming (STRATWARM) has a negative effect on medium
frequency propagation, due
to increasing medium frequency radio wave absorption by the D layer, via
upward propagating
Internal Gravity Waves (IGW).
Also I have observed that stratospheric warming usually coincides with major
jetstream circulation
pattern changes and movement of Arctic air masses from Siberian Russia
across the pole to Canada
and the U.S.
This phenomenon also occurs in southern hemisphere winter but seems to be
less pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-28
Published
1:00 PM EDT 02/10/13 For
02/10/14-02/10/20.
Though this
outlook is aimed primarily at medium frequencies, virtually all
the following
propagation data is applicable to HF frequencies.
7 DAY FORECAST
OUTLOOK-
During the previous 7 day period MF propagation conditions were
poor on
high latitude paths, fair on mid latitude paths and good
elsewhere.
During the outlook period overall improved MF propagation
conditions should
occur, as less absorptive geomagnetic activity is
expected.
Expect good domestic propagation conditions on east-west
paths and fair on
north-south paths in
the northern hemisphere out to
approximately 1050 miles.
Expect good domestic propagation conditions on
east-west paths and fair on
north-south paths in the
southern hemisphere
out to approximately 1050 miles.
"High latitude" northern hemispheric
(TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation
conditions in excess of approximately 3000 miles should be fair.
"High
latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and
cross equatorial
propagation conditions in excess of approximately 3000 miles
should be fair.
"Mid latitude" northern hemisphere (TA) Trans
Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions
in excess of approximately 3000 miles should be fair
to good.
"Mid
latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and
cross equatorial
propagation conditions in excess of approximately 3000 miles
should be fair
to good.
"Low latitude" northern hemisphere (TA)
Trans Atlantic, (TP) Trans Pacific
propagation conditions
in excess of
approximately 3000 miles should be good.
"Low latitude" southern
hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation
conditions
in excess of approximately 3000 miles should be
good.
There will be "moderate to high" lightning induced QRN levels
in mid and low
latitude areas of the
northern hemisphere tied to warm and
cold season thunderstorms, tropical
systems, cold/warm fronts
and
extra-tropical low pressure systems during the forecast period.
There
will be "moderate to high" lightning induced QRN levels in mid and
low
latitude areas of the
southern hemisphere tied to warm and cold season
thunderstorms, tropical
systems, cold/warm fronts
and extra-tropical low
pressure systems during the forecast period.
High to moderate lightning
induced QRN will continue in the vicinity of the
tropical ITCZ and
across
equatorial regions.
REVIEW-
The past seven day period was much
quieter overall and hopefully this trend
will continue as we
move
towards the upcoming summer/winter solstice.
ENERGETIC
PROTON FLUX-
During the previous seven day period no >10 MeV (10+0)
energetic proton
event occurred.
During the new outlook period the
probability of an elevated energetic
proton flux event >10 MeV (10+0) is
placed at 20%.
An elevated energetic proton flux level greater then
(10+0) on 160 meters
and greater then (10-1)
on the medium frequency
broadcast band creates noticeably increased winter
time day and year
round
night time D layer absorption of medium wave frequencies, especially on
high
latitude propagation
paths but it can also negatively impact mid
latitudes, depending on the
intensity of the event.
Elevated energetic
proton events too small to be categorized as a Polar Cap
Absorption event
(PCA)
can still impact high and mid level medium frequency propagation paths
in
the form of excessive D
layer absorption. This fact is still stubbornly
opposed by some otherwise
very knowledgeable space
weather physicists over
dependent on threshold Riometer readings.
((((Note, high latitude medium
frequency radio propagation paths can still
be disturbed for days
and up
to weeks, following the end of an official >10 MeV (10+0)
proton
event.))))
SOLAR FLUX-
During the previous 7
day period the daily solar flux values ranged between
184 and
160.
During the new outlook period the daily solar flux values should
range
between approximately 195 and 155.
NOTICE!!! During the outlook
period F2 layer propagation openings on 6
meters are improbable. Occasional
auroral propagation is probable, with
Sporadic E (Es) and Trans
Equatorial
Scatter (TEQ) openings also probable.
During the previous 7 day period
the background X-ray flux levels ranged
between B6.5 and
B5.3.
Elevated background X-ray flux levels can impact propagation of
medium
frequency signals in a
negative manner. Background X-ray flux
levels of C2 or greater creates
increased D-layer absorption
of 160 and
120 meter signals and C1 or greater creates increased D-layer
absorption of
AM broadcast
band signals.
High solar flux values are generally
considered to be detrimental to
propagation of medium
frequency signals
both domestic and Trans Atlantic (TA) & Trans Pacific
(TP), as
more
absorption can be present via the transmitted signals' two trips through
the
D layer at the takeoff
and arrival points.
Most "strong" longer
haul medium frequency DX signals in excess of 3000
miles is via the E
Valley-F
layer ducting and/or Chordal Hop propagation modes. Therefore high
solar
flux values can aid in
long haul medium frequency propagation paths
in excess of 3000 miles, as a
high solar flux value
ensures a strong F
layer part of the E Valley-F layer duct or Chordal Hop
propagation
mechanism.
However high solar activity in the form of increased
ionization created by
Ultraviolet and X-Ray
radiation can fill in the E
Valley region and interfere with the E Valley-F
layer ducting
mechanism.
In a sense the E Valley-F layer duct is closed on one or both
ends of a
propagation path
and the transmitted MF RF signal only propagates between the
E layer and
land/ocean surface, with a
higher angle and more
loss.
SUNSPOT REGIONS/SOLAR FLARES-
During the previous 7
day period no M class solar flares occurred. This is
and
unusual
occurrence during this point in the present sunspot
cycle.
Sunspot region #10139 at N08W59 contains a beta-gamma-delta class
magnetic
signature and harbors
energy for huge X class solar flares.
Fortunately though this group shows
signs of weakening and
will rotate
across the western limb of the Sun during the forecast period.
During the
outlook period I place the chance of a C class solar flare at
100%, an M
class at 60%
and an X class at 20%.
An earthward facing C4 or
higher class solar flare "can" elevate the proton
flux above 10 MeV
(10+0)
and initiate large scale high and mid latitude propagation path
absorption on
the AM
broadcast band, 160 and 120 meters, both stateside and DX, as a
transfer of
increased density and
RF signal absorption from the day
side D layer to night side of the
ionosphere occurs through high
level
neutral winds. Unfortunately even smaller C3 solar flares can create
hour to
hour and night to
night variations in signal strength on medium
frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific
(TP) propagation
paths tend to open up
after a significant period of time
passes without an elevated energetic
proton event of >10 MeV
(10+0).
This fact is still stubbornly opposed by some otherwise very
knowledgeable
space weather
physicists over dependent on threshold Riometer
readings.
Openings also occur when the solar background x-ray level falls
back to or
below C1 for 160 and 120
meters and B9 for the AM broadcast
band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE
AURORA-
During the previous 7 day period no geo-effective (Earth facing)
Coronal
Mass Ejections (CME) occurred.
During the previous 7 day
period our planet encountered a Solar Wind Stream
flowing from
a
geo-effective (Earth facing) coronal hole. This solar wind stream created
a
four day ionospheric storm with the Kp ranging between 4 (active) and
6
(moderate storm) and
ignited high and mid latitude visible Aurora
displays.
During the new outlook period a "small" geo-effective (Earth
facing) Coronal
Hole
and related Solar Wind Stream is expected to impact
the Earth's (IMF)
beginning on 02/10/14-15.
During the outlook period
the probability of a geo-effective (Earth facing)
Coronal Mass Ejection (CME)
is placed at 30%.
During the outlook period the probability of unsettled
to active (Kp-3/4)
geomagnetic conditions
is placed at 100%.
During
the outlook period the probability of at least a minor ionospheric
storm
(Kp-5)(G1) is placed at 60%.
During the outlook period the probability of
at least a moderate ionospheric
storm (Kp-6)(G2) is placed at
40%.
During the outlook period the probability of at least a strong
ionospheric
storm (Kp-7+)(G3+) is placed at 20%.
G5 = Extreme - Kp =
9
G4 = Severe - Kp = 8
G3 = Strong - Kp = 7
G2 = Moderate - Kp =
6
G1 = Minor - Kp = 5
    Active - Kp = 4
    Unsettled - Kp =
3
During the outlook period the probability of a visible mid latitude
Aurora
display is placed at 40%.
At 1547 UTC on 02/10/13 the Bz is 5.7
nt south.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model
which predicts
Earth's IMF polarity, forecasts a negative (-) polarity
from
02/10/15-02/10/20.
When the polarity of the IMF is negative a
visible mid latitude Aurora
display is likely when a CME
strikes the
Earth's magnetic field. When the polarity of the IMF is positive
a visible
mid latitude
Aurora display is unlikely as a CME strikes the Earth's magnetic
field.
A Coronal Mass Ejection is the name given to an ejection of a
large amount
of matter from the Sun's
outer atmosphere or corona. These
ejections typically comprise millions of
tons of material in the
form of
charged particles, and can be seen because the material reflects
sunlight.
When one
of these ejections is directed towards the Earth (or conversely,
directly
away from the Earth), it
looks like a roughly circular "halo"
surrounding the Sun.
The "Halo CME's" then are those CME's which are more
likely to impact the
Earth than those which
are shot out at right angles
to the Earth-Sun line. Energetic protons
emitted during CME's play a
major
role in increased day time and night-time D-layer absorption of
mediumwave
frequencies.
Coronal Mass Ejections were once thought to be completely
initiated by solar
flares. However it is
now known that many (CME's) are
not associated with Solar Flares. If a (CME)
collides with the
Earth, it
can excite a Geomagnetic Storm if the polarity of the IMF has a
negative
sign. We must be
vigilant in watching for geoeffective (CME's), in order to
not be caught by
surprise with a
seemingly sudden and unexpected
Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins
expanding equatorward in
magnetic latitude and
generally begins having a
negative impact on high latitude medium frequency
propagation paths. A
Kp
index of 5 or higher begins to have a negative impact on high latitude
high
frequency shortwave
propagation paths. However at times skewed path
propagation conditions can
compensate for high
latitude propagation path
auroral absorption.
STRATOSPHERIC WARMING-
During the outlook
period increased winter like day and year round night
time D layer absorption
of
medium frequency signals tied to stratospheric warming in the
northern
hemisphere is possible, due to a large scale movement of Arctic air
across
the North Pole from
Siberian Russia into
Canada.
Stratospheric warming is a major temperature change of the
winter time polar
and middle atmosphere
from the tropopause (where the
troposphere transitions into the
stratosphere) to the base (D-layer)
of
the ionosphere, lasting for many days at a time and characterized by
a
warming of the
stratospheric temperature by some tens of degrees
(temperature inversion).
As the stratosphere lies below the ionosphere, which
is at mesosphere and
thermosphere height, you
would not expect to see
stratospheric warming effect medium frequency
propagation in any way
BUT
medium frequency signals do refract off of temperature inversions
and
moisture discontinuities and
a temperature inversion is involved with
stratospheric warming. So it's
possible that a medium
frequency signal
could do any number of things when refracting off of a
temperature inversion,
at
any height.
Also stratospheric warming (STRATWARM) has a negative
effect on medium
frequency propagation, due
to increasing medium frequency
radio wave absorption by the D layer, via
upward propagating
Internal
Gravity Waves (IGW).
Also I have observed that stratospheric warming
usually coincides with major
jetstream circulation
pattern changes and
movement of Arctic air masses from Siberian Russia
across the pole to
Canada
and the U.S.
This phenomenon also occurs in southern hemisphere
winter but seems to be
less pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-27
Published
5:00 PM EDT 02/10/06 For
02/10/07-02/10/13.
Though this
outlook is aimed primarily at medium frequencies, virtually all
the
following
propagation data is applicable to HF frequencies.
This 7 day
medium frequency (300-3000 kc) propagation outlook and other
solar, space
weather and
propagation data can be found on my website at
http://www.kn4lf.com/kn4lf5.htm
.
Due to the international scope of the Amateur Radio/SWL radio community
I
have adopted the date
format of yy/mm/dd.
With this outlook I
will begin placing the actual propagation forecast at
the beginning,
with
the previous weeks data and educational propagation explanations
thereafter,
as not everyone
is interested in the rest of the
outlook.
REVIEW-
Well I opened my big mouth by commenting on how
the two week period of
02/09/16-02/09/29
was very quiet, considering that
we were at the Fall/Spring Equinox. This
two week period produced
for the
best MF and HF radio propagation conditions in the past three years.
Now we
come to the week of 02/09/30-02/10/06 and BANG!!! massive long
lived
absorptive auroral
conditions and ionospheric storms, courtesy of a
coronal hole that I
correctly identified as a
future problem but
underestimated it's actual negative impact.
7 DAY FORECAST
OUTLOOK-
As we are still near the Fall/Spring Equinox propagation
conditions are more
balanced in both
hemispheres but as is also the norm
geomagnetic activity increases and as we
know the previous 7
day period
was very active.
During the previous 7 day period MF propagation
conditions were very poor on
high latitude paths,
poor to fair on mid
latitude paths and good elsewhere.
During the outlook period overall poor
MF propagation conditions should
continue, as more
absorptive geomagnetic
activity is expected.
Expect good domestic propagation conditions on
east-west paths and fair on
north-south paths in
the northern hemisphere
out to approximately 1050 miles.
Expect good domestic propagation
conditions on east-west paths and fair on
north-south paths in
the
southern hemisphere out to approximately 1050 miles.
"High
latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and
cross equatorial
propagation conditions in excess of approximately 3000 miles
should be poor.
"High latitude" southern hemispheric (TA) Trans Atlantic,
(TP) Trans Pacific
and cross equatorial
propagation conditions in excess
of approximately 3000 miles should be poor.
"Mid latitude" northern
hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross
equatorial
propagation conditions in excess of approximately 3000 miles
should be fair.
"Mid latitude" southern hemisphere (TA) Trans Atlantic,
(TP) Trans Pacific
and cross equatorial
propagation conditions in excess
of approximately 3000 miles should be fair.
"Low latitude" northern
hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation
conditions
in excess of approximately 3000 miles should be good.
"Low
latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans
Pacific
propagation conditions
in excess of approximately 3000 miles
should be good.
There will be "moderate to high" lightning induced
QRN levels in mid and low
latitude areas of the
northern hemisphere tied
to warm and cold season thunderstorms, tropical
systems, cold/warm
fronts
and extra-tropical low pressure systems during the forecast
period.
There will be "moderate to high" lightning induced QRN levels in
mid and low
latitude areas of the
southern hemisphere tied to warm and
cold season thunderstorms, tropical
systems, cold/warm fronts
and
extra-tropical low pressure systems during the forecast period.
High to
moderate lightning induced QRN will continue in the vicinity of the
tropical
ITCZ and
across equatorial regions.
ENERGETIC PROTON
FLUX-
During the previous seven day period no >10 MeV (10+0) energetic
proton
event occurred.
During the new outlook period the probability
of an elevated energetic
proton flux event >10 MeV
(10+0) is placed at
30%.
An elevated energetic proton flux level greater then (10+0) on
160 meters
and greater then (10-1)
on the medium frequency broadcast band
creates noticeably increased winter
time day and year round
night time D
layer absorption of medium wave frequencies, especially on high
latitude
propagation
paths but it can also negatively impact mid latitudes, depending
on the
intensity of the event.
Elevated energetic proton events too
small to be categorized as a Polar Cap
Absorption event (PCA)
can still
impact high and mid level medium frequency propagation paths in
the form of
excessive D
layer absorption. This fact is still stubbornly opposed by some
otherwise
very knowledgeable space
weather physicists over dependent on
threshold Riometer readings.
((((Note, high latitude medium frequency
radio propagation paths can still
be disturbed for days
and up to weeks,
following the end of an official >10 MeV (10+0)
proton
event.))))
SOLAR FLUX-
During the month of
September the daily solar flux ranges between 221 and
136. During the
previous
7 day period the daily solar flux values ranged between 172 and
136.
During the new outlook period the daily solar flux values should
range
between approximately 200
and 135.
NOTICE!!! During the
outlook period F-1/2 layer propagation openings on 6
meters are
improbable.
Occasional auroral propagation is probable, with Sporadic E (Es)
and Trans
Equatorial Scatter (TEQ)
openings also probable.
During
the previous 7 day period the background X-ray flux levels ranged
between
C1.1 and B4.6.
Elevated background X-ray flux levels can impact
propagation of medium
frequency signals in a
negative manner. Background
X-ray flux levels of C2 or greater creates
increased D-layer absorption
of
160 and 120 meter signals and C1 or greater creates increased
D-layer
absorption of AM broadcast
band signals.
High solar flux
values are generally considered to be detrimental to
propagation of
medium
frequency signals both domestic and Trans Atlantic (TA) &
Trans Pacific
(TP), as more
absorption can be present via the transmitted
signals' two trips through the
D layer at the takeoff
and arrival
points.
Most "strong" longer haul medium frequency DX signals in excess
of 3000
miles is via the E Valley-F
layer ducting and/or Chordal Hop
propagation modes. Therefore high solar
flux values can aid in
long haul
medium frequency propagation paths in excess of 3000 miles, as a
high solar
flux value
ensures a strong F layer part of the E Valley-F layer duct or
Chordal Hop
propagation mechanism.
However high solar activity in the
form of increased ionization created by
Ultraviolet and X-Ray
radiation
can fill in the E Valley region and interfere with the E Valley-F
layer
ducting
mechanism. In a sense the E Valley-F layer duct is closed on one or
both
ends of a propagation path
and the transmitted MF RF signal only
propagates between the E layer and
land/ocean surface, with a
higher angle
and more loss.
SUNSPOT REGIONS/SOLAR FLARES-
During the
previous 7 day period ten M class solar flares occurred.
The largest was
a M5.9 solar flare which occurred at 2049-2129 UTC
on
02/10/05.
Sunspot region #10137 located at S11W33 and #10139 at
N12E32 both contain a
beta-gamma class
magnetic signatures and harbor
energy for medium sized M class solar flares.
Earlier in the week
both
sunspot regions developed delta class magnetic signatures and also
could
still release
isolated but huge X class solar flares.
During the
outlook period I place the chance of a C class solar flare at
100%, an M
class at 70%
and an X class at 20%.
An earthward facing C4 or
higher class solar flare "can" elevate the proton
flux above 10 MeV
(10+0)
and initiate large scale high and mid latitude propagation path
absorption on
the AM
broadcast band, 160 and 120 meters, both stateside and DX, as a
transfer of
increased density and
RF signal absorption from the day
side D layer to night side of the
ionosphere occurs through high
level
neutral winds. Unfortunately even smaller C3 solar flares can create
hour to
hour and night to
night variations in signal strength on medium
frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific
(TP) propagation
paths tend to open up
after a significant period of time
passes without an elevated energetic
proton event of >10 MeV
(10+0).
This fact is still stubbornly opposed by some otherwise very
knowledgeable
space weather
physicists over dependent on threshold Riometer
readings.
Openings also occur when the solar background x-ray level falls
back to or
below C1 for 160 and 120
meters and B9 for the AM broadcast
band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE
AURORA-
During the previous 7 day period one geo-effective (Earth facing)
Coronal
Mass Ejections (CME)
occurred on 02/10/02, sending the Bz
southward.
A second partially geo-effective (Earth facing) Coronal Mass
Ejection (CME),
tied to the M5.9 solar
flare on 02/10/05 may send the Bz
southward again within 24 hours.
During the previous 7 day period our
planet encountered a Solar Wind Stream
flowing from a
geo-effective (Earth
facing) coronal hole. This solar wind stream created a
six day
ionospheric
storm with the Kp ranging between 4 (active) and 7 (major
storm) and ignited
widespread high and
mid latitude visible Aurora
displays.
During the new outlook period a geo-effective (Earth facing)
Coronal Hole
and related Solar Wind
Stream is expected to impact the
Earth's (IMF) beginning on 02/10/06-08.
During the outlook period the
probability of a geo-effective (Earth facing)
Coronal Mass Ejection
(CME)
is placed at 50%.
During the outlook period the probability of unsettled
(Kp-3) to active
(Kp-4) geomagnetic
conditions is placed at
100%.
During the outlook period the probability of at least a moderate
ionospheric
storm (Kp-5)(G1) is
placed at 70%.
During the outlook
period the probability of a visible mid latitude Aurora
display is placed
at
70%.
At 2000 UTC on 02/09/29 the Bz is 3.6 nt south.
The
Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
Earth's
IMF polarity,
forecasts a positive polarity from
02/10/07-02/10/13.
When the polarity of the IMF is negative a
visible mid latitude Aurora
display is likely when a CME
strikes the
Earth's magnetic field. When the polarity of the IMF is positive
a visible
mid latitude
Aurora display is unlikely as a CME strikes the Earth's magnetic
field.
A Coronal Mass Ejection is the name given to an ejection of a
large amount
of matter from the Sun's
outer atmosphere or corona. These
ejections typically comprise millions of
tons of material in the
form of
charged particles, and can be seen because the material reflects
sunlight.
When one
of these ejections is directed towards the Earth (or conversely,
directly
away from the Earth), it
looks like a roughly circular "halo"
surrounding the Sun.
The "Halo CME's" then are those CME's which are more
likely to impact the
Earth than those which
are shot out at right angles
to the Earth-Sun line. Energetic protons
emitted during CME's play a
major
role in increased day time and night-time D-layer absorption of
mediumwave
frequencies.
Coronal Mass Ejections were once thought to be completely
initiated by solar
flares. However it is
now known that many (CME's) are
not associated with Solar Flares. If a (CME)
collides with the
Earth, it
can excite a Geomagnetic Storm if the polarity of the IMF has a
negative
sign. We must be
vigilant in watching for geoeffective (CME's), in order to
not be caught by
surprise with a
seemingly sudden and unexpected
Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins
expanding equatorward in
magnetic latitude and
generally begins having a
negative impact on high latitude medium frequency
propagation paths. A
Kp
index of 5 or higher begins to have a negative impact on high latitude
high
frequency shortwave
propagation paths. However at times skewed path
propagation conditions can
compensate for high
latitude propagation path
auroral absorption.
STRATOSPHERIC WARMING-
During the outlook
period increased winter like day and year round night
time D layer absorption
of
medium frequency signals tied to stratospheric warming in the
northern
hemisphere is possible
mainly over
Europe.
Stratospheric warming is a major temperature change of
the winter time polar
and middle atmosphere
from the tropopause (where the
troposphere transitions into the
stratosphere) to the base (D-layer)
of
the ionosphere, lasting for many days at a time and characterized by
a
warming of the
stratospheric temperature by some tens of degrees
(temperature inversion).
As the stratosphere lies below the ionosphere, which
is at mesosphere and
thermosphere height, you
would not expect to see
stratospheric warming effect medium frequency
propagation in any way
BUT
medium frequency signals do refract off of temperature inversions
and
moisture discontinuities and
a temperature inversion is involved with
stratospheric warming. So it's
possible that a medium
frequency signal
could do any number of things when refracting off of a
temperature inversion,
at
any height.
Also stratospheric warming (STRATWARM) has a negative
effect on medium
frequency propagation, due
to increasing medium frequency
radio wave absorption by the D layer, via
upward propagating
Internal
Gravity Waves (IGW).
Also I have observed that stratospheric warming
usually coincides with major
jetstream circulation
pattern changes and
movement of Arctic air masses from Siberian Russia
across the pole to
Canada
and the U.S.
This phenomenon also occurs in southern hemisphere
winter but seems to be
less pronounced.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-26
Published
2:00 PM EDT 02/09/29 For 02/09/30-02/10/06.
Though this outlook is aimed
primarily at medium frequencies, virtually all
the following propagation data
is applicable to HF frequencies.
Due to the international scope of the
Amateur Radio/SWL radio community I
have adopted the date format of
yy/mm/dd.
REVIEW-
The week of 02/09/23-02/09/29 was very quiet
considering that we are now
just past the Fall/Spring Equinox. Also MF radio
propagation conditions were
very good, the best in a long time, HF
too.
ENERGETIC PROTON FLUX-
During the previous seven day
period no >10 MeV (10+0) energetic proton
event occurred.
During
the new outlook period the probability of an elevated energetic
proton flux
event >10 MeV (10+0) is placed at 30%.
An elevated energetic
proton flux level greater then (10+0) on 160 meters
and greater then (10-1)
on the medium frequency broadcast band creates
noticeably increased winter
time day and year round night time D layer
absorption of medium wave
frequencies, especially on high latitude
propagation paths but it can also
negatively impact mid latitudes, depending
on the intensity of the event.
Elevated energetic proton events too small to
be categorized as a Polar Cap
Absorption event (PCA) can still impact high
and mid level medium frequency
propagation paths in the form of excessive D
layer absorption. This fact is
still stubbornly opposed by some otherwise
very knowledgeable space weather
physicists over dependent on threshold
Riometer readings.
((((Note,
high latitude medium frequency radio propagation paths can still
be disturbed
for days and up to weeks, following the end of an official >10
MeV (10+0)
proton event.))))
SOLAR FLUX-
During the previous 7 day
period the daily solar flux values ranged between
162 and 136.
During
the new outlook period the daily solar flux values should range
between
approximately 200 and 130.
-----
NOTICE!!! During the outlook period F-1/2
layer propagation openings on 6
meters are improbable. However daily solar
flux values may support some F2
layer propagation during the week of October
7-14, 2002.
-----
Occasional auroral propagation is probable, with
Sporadic E (Es) and Trans
Equatorial Scatter (TEQ) openings also
probable.
During the previous 7 day period the background X-ray flux
levels ranged
between C1.3 and B4.8.
Elevated background X-ray
flux levels can impact propagation of medium
frequency signals in a negative
manner. Background X-ray flux levels of C2
or greater creates increased
D-layer absorption of 160 and 120 meter signals
and C1 or greater creates
increased D-layer absorption of AM broadcast band
signals.
High solar
flux values are generally considered to be detrimental to
propagation of
medium frequency signals both domestic and Trans Atlantic
(TA) &
Trans Pacific (TP), as more absorption can be present via the
transmitted
signals' two trips through the D layer at the takeoff and
arrival
points.
Most "strong" longer haul medium frequency DX signals in excess
of 3000
miles is via the E Valley-F layer ducting and/or Chordal Hop
propagation
modes. Therefore high solar flux values can aid in long haul
medium
frequency propagation paths in excess of 3000 miles, as a high solar
flux
value ensures a strong F layer part of the E Valley-F layer duct or
Chordal
Hop propagation mechanism.
However high solar activity in the
form of increased ionization created by
Ultraviolet and X-Ray radiation can
fill in the E Valley region and
interfere with the E Valley-F layer ducting
mechanism. In a sense the E
Valley-F layer duct is closed on one or both ends
of a propagation path and
the transmitted MF RF signal only propagates
between the E layer and
land/ocean surface, with a higher angle and more
loss.
SUNSPOT REGIONS/SOLAR FLARES-
During the previous 7
day period three M class and to strong C class solar
flares
occurred.
The largest was a M2.7 solar flare which occurred at 0634-0644
UTC on
02/09/29.
Sunspot region #10134 located at N11E15 contains a
beta-gamma-delta class
magnetic signature and harbors energy for medium sized
M class solar flares
and also possibly isolated huge X class solar
flares.
During the outlook period I place the chance of a C class solar
flare at
100%, an M class at 50% and an X class at 30%.
An
earthward facing C4 or higher class solar flare "can" elevate the proton
flux
above 10 MeV (10+0) and initiate large scale high and mid
latitude
propagation path absorption on the AM broadcast band, 160 and 120
meters,
both stateside and DX, as a transfer of increased density and RF
signal
absorption from the day side D layer to night side of the ionosphere
occurs
through high level neutral winds. Unfortunately even smaller C3 solar
flares
can create hour to hour and night to night variations in signal
strength on
medium frequencies.
High and mid latitude Trans Atlantic
(TA) and Trans Pacific (TP) propagation
paths tend to open up after a
significant period of time passes without an
elevated energetic proton event
of >10 MeV (10+0). This fact is still
stubbornly opposed by some otherwise
very knowledgeable space weather
physicists over dependent on threshold
Riometer readings.
Openings also occur when the solar background x-ray
level falls back to or
below C1 for 160 and 120 meters and B9 for the AM
broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE
AURORA-
During the previous 7 day period no geo-effective (Earth facing)
Coronal
Mass Ejection (CME) impacted the Earth. However numerous non
geo-effective
(Earth facing)CME's did occur.
During the previous 7 day
period our planet did not encounter a Solar Wind
Stream flowing from a
geo-effective (Earth facing) coronal hole.
During the new outlook period
a geo-effective (Earth facing) Coronal Hole
and related Solar Wind Stream is
expected beginning on 02/09/29-30.
During the outlook period the
probability of a geo-effective (Earth facing)
Coronal Mass Ejection (CME) is
placed at 20%.
During the outlook period the probability of unsettled
(Kp-3) to active
(Kp-4) geomagnetic conditions is placed at
40%.
During the outlook period the probability of at least a moderate
ionospheric
storm (Kp-5)(G1) is placed at 30%.
During the outlook
period the probability of a visible mid latitude Aurora
display is placed at
30%.
At 1800 UTC on 02/09/29 the Bz is 1.6 nt south.
The
Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
Earth's
IMF polarity, forecasts a positive polarity from
02/09/29-02/10/06.
When the polarity of the IMF is negative a visible
mid latitude Aurora
display is likely when a CME strikes the Earth's magnetic
field. When the
polarity of the IMF is positive a visible mid latitude Aurora
display is
unlikely as a CME strikes the Earth's magnetic field.
A
Coronal Mass Ejection is the name given to an ejection of a large amount
of
matter from the Sun's outer atmosphere or corona. These ejections
typically
comprise millions of tons of material in the form of charged
particles, and
can be seen because the material reflects sunlight. When one
of these
ejections is directed towards the Earth (or conversely, directly
away from
the Earth), it looks like a roughly circular "halo" surrounding
the
Sun.
The "Halo CME's" then are those CME's which are more likely to
impact the
Earth than those which are shot out at right angles to the
Earth-Sun line.
Energetic protons emitted during CME's play a major role in
increased day
time and night-time D-layer absorption of mediumwave
frequencies.
Coronal Mass Ejections were once thought to be completely
initiated by solar
flares. However it is now known that many (CME's) are not
associated with
Solar Flares. If a (CME) collides with the Earth, it can
excite a
Geomagnetic Storm if the polarity of the IMF has a negative sign. We
must be
vigilant in watching for geoeffective (CME's), in order to not be
caught by
surprise with a seemingly sudden and unexpected Geomagnetic
Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding
equatorward in
magnetic latitude and
generally begins having a negative
impact on high latitude medium frequency
propagation paths. A Kp index of 5
or higher begins to have a negative
impact on high latitude high frequency
shortwave propagation paths. However
at times skewed path propagation
conditions can compensate for high latitude
propagation path auroral
absorption.
STRATOSPHERIC WARMING-
During the outlook period
increased winter like day and year round night
time D layer absorption of
medium frequency signals tied to stratospheric
warming in the northern
hemisphere is possible.
Stratospheric warming is a major temperature
change of the winter time polar
and middle atmosphere from the tropopause
(where the troposphere transitions
into the stratosphere) to the base
(D-layer) of the ionosphere, lasting for
many days at a time and
characterized by a warming of the stratospheric
temperature by some tens of
degrees (temperature inversion).
As the stratosphere lies below the
ionosphere, which is at mesosphere and
thermosphere height, you would not
expect to see stratospheric warming
effect medium frequency propagation in
any way BUT medium frequency signals
do refract off of temperature inversions
and moisture discontinuities and a
temperature inversion is involved with
stratospheric warming. So it's
possible that a medium
frequency signal
could do any number of things when refracting off of a
temperature inversion,
at any height.
Also stratospheric warming (STRATWARM) has a negative
effect on medium
frequency propagation, due to increasing medium frequency
radio wave
absorption by the D layer, via upward propagating Internal Gravity
Waves
(IGW).
Also I have observed that stratospheric warming usually
coincides with major
jetstream circulation pattern changes and movement of
Arctic air masses from
Siberian Russia across the pole to Canada and the
U.S.
This phenomenon also occurs in southern hemisphere winter but seems
to be
less pronounced.
7 DAY FORECAST OUTLOOK-
As we
are at the fall/spring equinox propagation conditions are more
balanced in
both hemispheres but as is the norm geomagnetic
activity
increases.
During the previous 7 day period MF propagation
conditions were very good,
probably better then all of the 2001-2002 DX
season.
During the outlook period very good MF propagation conditions
should
continue.
Expect very good domestic propagation conditions
in the northern hemisphere
out to approximately 1050 miles.
Expect
very good domestic propagation conditions in the southern hemisphere
out to
approximately 1050 miles.
"High latitude" northern hemispheric (TA)
Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation
conditions in excess of approximately 3000
miles should be good.
"High
latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and
cross equatorial propagation conditions in excess of approximately 3000
miles
should be good.
"Mid latitude" northern hemisphere (TA) Trans
Atlantic, (TP) Trans Pacific
and cross equatorial propagation conditions in
excess of approximately 3000
miles should be good to very good.
"Mid
latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and
cross equatorial propagation conditions in excess of approximately 3000
miles
should be good to very good.
"Low latitude" northern hemisphere (TA)
Trans Atlantic, (TP) Trans Pacific
propagation conditions in excess of
approximately 3000 miles should be very
good.
"Low latitude" southern
hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in
excess of approximately 3000 miles should be very
good.
There will
be "moderate to high" lightning induced QRN levels in mid and low
latitude
areas of the northern hemisphere tied to warm and cold season
thunderstorms,
tropical systems, cold/warm fronts and extra-tropical low
pressure systems
during the forecast period.
There will be "moderate to high" lightning
induced QRN levels in mid and low
latitude areas of the southern hemisphere
tied to warm and cold season
thunderstorms, tropical systems, cold/warm
fronts and extra-tropical low
pressure systems during the forecast
period.
High to moderate lightning induced QRN will continue in the
vicinity of the
tropical ITCZ and across equatorial
regions.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-25
Published
4:00 PM EDT 02/09/22 For 02/09/23-02/09/29.
Though this outlook is aimed
primarily at medium frequencies, virtually all
the following
propagation
data is applicable to HF frequencies.
Due to the international scope of the Amateur Radio/SWL radio community
I
have adopted the date
format of yy/mm/dd.
REVIEW-
The week
of 02/09/16-02/09/22 was quiet considering that we are at the
Fall/Spring
Equinox. The Fall/Spring Equinox begins on 02/09/23 at 0455
UTC.
ENERGETIC PROTON FLUX-
During the previous seven day
period no >10 MeV (10+0) energetic proton
event occurred.
During
the new outlook period the probability of an elevated energetic
proton flux
event >10 MeV
(10+0) is placed at 40%.
An elevated energetic
proton flux level greater then (10+0) on 160 meters
and greater then
(10-1)
on the medium frequency broadcast band creates noticeably increased
winter
time day and year round
night time D layer absorption of medium
wave frequencies, especially on high
latitude propagation
paths but it can
also negatively impact mid latitudes, depending on the
intensity of the
event.
Elevated energetic proton events too small to be categorized as a
Polar Cap
Absorption event (PCA)
can still impact high and mid level
medium frequency propagation paths in
the form of excessive D
layer
absorption. This fact is still stubbornly opposed by some otherwise
very
knowledgeable space
weather physicists over dependent on threshold Riometer
readings.
((((Note, high latitude medium frequency radio propagation
paths can still
be disturbed for days
and up to weeks, following the end
of an official >10 MeV (10+0) proton
event.))))
SOLAR
FLUX-
During the previous 7 day period the daily solar flux values ranged
between
194 and 159.
During the new outlook period the daily solar
flux values should range
between approximately 200
and
150.
NOTICE!!! During the outlook period F-1/2 layer propagation openings
on 6
meters are improbable.
Occasional auroral propagation is
probable, with Sporadic E (Es) and Trans
Equatorial Scatter
(TEQ)
openings also probable.
During the previous 7 day period the
background X-ray flux levels ranged
between C1.1 and
B6.4.
Elevated background X-ray flux levels can impact
propagation of medium
frequency signals in a
negative manner. Background
X-ray flux levels of C2 or greater creates
increased D-layer absorption
of
160 and 120 meter signals and C1 or greater creates increased
D-layer
absorption of AM broadcast
band signals.
High solar flux
values are generally considered to be detrimental to
propagation of
medium
frequency signals both domestic and Trans Atlantic (TA) &
Trans Pacific
(TP), as more
absorption can be present via the transmitted
signals' two trips through the
D layer at the takeoff
and arrival
points.
Most "strong" longer haul medium frequency DX signals in excess
of 3000
miles is via the E Valley-F
layer ducting and/or Chordal Hop
propagation modes. Therefore high solar
flux values can aid in
long haul
medium frequency propagation paths in excess of 3000 miles, as a
high solar
flux value
ensures a strong F layer part of the E Valley-F layer duct or
Chordal Hop
propagation mechanism.
However high solar activity in the form
of increased ionization created by
Ultraviolet and X-Ray
radiation can
fill in the E Valley region and interfere with the E Valley-F
layer
ducting
mechanism. In a sense the E Valley-F layer duct is closed on one or
both
ends of a propagation path
and the transmitted MF RF signal only
propagates between the E layer and
land/ocean surface, with a
higher angle
and more loss.
SUNSPOT REGIONS/SOLAR FLARES-
During the
previous 7 day period three M class solar flares occurred.
The largest
was a M1.7 solar flare which occurred at 0924-0934 UTC
on
02/09/20.
Sunspot region #10119 located at S14W36 contains a
beta-gamma-delta class
magnetic signature and
harbors energy for medium
sized M class solar flares and also huge X class
solar flares.
Sunspot
region #10127 located at S14W05 contains a beta-gamma class
magnetic
signature, harbors
energy for medium sized M class solar
flares.
During the outlook period I place the chance of a C class solar
flare at
100%, an M class at 50%
and an X class at 30%.
An
earthward facing C4 or higher class solar flare "can" elevate the proton
flux
above 10 MeV
(10+0) and initiate large scale high and mid latitude
propagation path
absorption on the AM
broadcast band, 160 and 120 meters,
both stateside and DX, as a transfer of
increased density and
RF signal
absorption from the day side D layer to night side of the
ionosphere occurs
through high
level neutral winds. Unfortunately even smaller C3 solar flares
can create
hour to hour and night to
night variations in signal strength
on medium frequencies.
High and mid latitude Trans Atlantic (TA) and
Trans Pacific (TP) propagation
paths tend to open up
after a significant
period of time passes without an elevated energetic
proton event of >10
MeV
(10+0). This fact is still stubbornly opposed by some otherwise
very
knowledgeable space weather
physicists over dependent on threshold
Riometer readings.
Openings also occur when the solar background x-ray
level falls back to or
below C1 for 160 and 120
meters and B9 for the AM
broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE
AURORA-
During the previous 7 day period one geo-effective (Earth facing)
Coronal
Mass Ejection (CME)
impacted the Earth. The CME left the Sun on
02/09/17. It's interplanetary
shock wave swept past
Earth on 02/09/19 at
0600 UTC, creating active geomagnetic conditions (KP-4)
but did not
trigger
widespread visible Aurora as the polarity of the IMF was
positive.
During the previous 7 day period our planet did not encounter a
Solar Wind
Stream flowing from a
geo-effective (Earth facing) coronal
hole.
During the new outlook period no geo-effective (Earth facing)
Coronal Holes
and related Solar Wind
Streams are expected.
During
the outlook period the probability of a geo-effective (Earth facing)
Coronal
Mass Ejection
(CME) is placed at 40%.
During the outlook period the
probability of unsettled (Kp-3) to active
(Kp-4) geomagnetic
conditions is
placed at 40%.
During the outlook period the probability of at least a
moderate ionospheric
storm (Kp-5)(G1) is
placed at 40%.
During the
outlook period the probability of a visible mid latitude Aurora
display is
placed at
40%.
The Wang-Sheeley Interplanetary Magnetic Field (IMF)
Model which predicts
Earth's IMF polarity,
forecasts a negative polarity
from 02/09/23-02/09/29.
When the polarity of the IMF is negative a
visible mid latitude Aurora
display is likely when a CME
strikes the
Earth's magnetic field. When the polarity of the IMF is positive
a visible
mid latitude
Aurora display is unlikely as a CME strikes the Earth's magnetic
field.
A Coronal Mass Ejection is the name given to an ejection of a
large amount
of matter from the Sun's
outer atmosphere or corona. These
ejections typically comprise millions of
tons of material in the
form of
charged particles, and can be seen because the material reflects
sunlight.
When one
of these ejections is directed towards the Earth (or conversely,
directly
away from the Earth), it
looks like a roughly circular "halo"
surrounding the Sun.
The "Halo CME's" then are those CME's which are more
likely to impact the
Earth than those which
are shot out at right angles
to the Earth-Sun line. Energetic protons
emitted during CME's play a
major
role in increased day time and night-time D-layer absorption of
mediumwave
frequencies.
Coronal Mass Ejections were once thought to be completely
initiated by solar
flares. However it is
now known that many (CME's) are
not associated with Solar Flares. If a (CME)
collides with the
Earth, it
can excite a Geomagnetic Storm if the polarity of the IMF has a
negative
sign. We must be
vigilant in watching for geoeffective (CME's), in order to
not be caught by
surprise with a
seemingly sudden and unexpected
Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins
expanding equatorward in
magnetic latitude and
generally begins having a
negative impact on high latitude medium frequency
propagation paths. A
Kp
index of 5 or higher begins to have a negative impact on high latitude
high
frequency shortwave
propagation paths. However at times skewed path
propagation conditions can
compensate for high
latitude propagation path
auroral absorption.
STRATOSPHERIC WARMING-
During the outlook
period increased winter like day and year round night
time D layer absorption
of
medium frequency signals tied to stratospheric warming should not
occur.
Stratospheric warming is a major temperature change of the
winter time polar
and middle atmosphere
from the tropopause (where the
troposphere transitions into the
stratosphere) to the base (D-layer)
of
the ionosphere, lasting for many days at a time and characterized by
a
warming of the
stratospheric temperature by some tens of degrees
(temperature inversion).
As the stratosphere lies below the ionosphere,
which is at mesosphere and
thermosphere height, you
would not expect to
see stratospheric warming effect medium frequency
propagation in any way
BUT
medium frequency signals do refract off of temperature inversions
and
moisture discontinuities and
a temperature inversion is involved with
stratospheric warming. So it's
possible that a medium
frequency signal
could do any number of things when refracting off of a
temperature inversion,
at
any height.
Also stratospheric warming (STRATWARM) has a negative
effect on medium
frequency propagation, due
to increasing medium frequency
radio wave absorption by the D layer, via
upward propagating
Internal
Gravity Waves (IGW).
Also I have observed that stratospheric warming
usually coincides with major
jetstream circulation
pattern changes and
movement of Arctic air masses from Siberian Russia
across the pole to
Canada
and the U.S.
This phenomenon also occurs in southern hemisphere
winter but seems to be
less pronounced.
7 DAY FORECAST
OUTLOOK-
As we are at the fall/spring equinox propagation conditions are
more
balanced in both hemispheres. Also as is the norm geomagnetic activity
will
continue to increase.
Expect very good domestic propagation
conditions in the northern hemisphere
out to approximately
1050
miles.
Expect very good domestic propagation conditions in the southern
hemisphere
out to approximately
1050 miles.
"High latitude"
northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross
equatorial
propagation conditions in excess of approximately 3000 miles
should be good.
"High latitude" southern hemispheric (TA) Trans Atlantic,
(TP) Trans Pacific
and cross equatorial
propagation conditions in excess
of approximately 3000 miles should be good.
"Mid latitude" northern
hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross
equatorial
propagation conditions in excess of approximately 3000 miles
should be good
to very good.
"Mid latitude" southern hemisphere (TA)
Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation
conditions in excess of approximately 3000 miles should be good
to very
good.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP)
Trans Pacific
propagation conditions
in excess of approximately 3000 miles
should be very good.
"Low latitude" southern hemisphere (TA) Trans
Atlantic, (TP) Trans Pacific
propagation conditions
in excess of
approximately 3000 miles should be very good.
There will be "moderate
to high" lightning induced QRN levels in mid and low
latitude areas of
the
northern hemisphere tied to warm and cold season thunderstorms,
tropical
systems, cold/warm fronts
and extra-tropical low pressure systems
during the forecast period.
There will be "moderate to high" lightning
induced QRN levels in mid and low
latitude areas of the
southern
hemisphere tied to warm and cold season thunderstorms, tropical
systems,
cold/warm fronts
and extra-tropical low pressure systems during the forecast
period.
High to moderate lightning induced QRN will continue in the
vicinity of the
tropical ITCZ and
across equatorial
regions.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-24 Published
7:00 PM EDT 02/09/15 For
02/09/16-02/09/22.
Though this outlook is aimed primarily at medium frequencies, virtually all
the following
propagation data is applicable to HF frequencies.
This 7 day medium frequency (300-3000 kc) propagation outlook and other
solar, space weather and
propagation data can be found on my website at
http://www.kn4lf.com/kn4lf5.htm .
Due to the international scope of the Amateur Radio/SWL radio community I
have adopted the date
format of yy/mm/dd.
REVIEW-
The week of 02/09/09-02/09/15 was relatively quiet considering that we are
approaching the Fall/Spring Equinox.
ENERGETIC PROTON FLUX-
During the previous seven day period no >10 MeV (10+0) energetic proton
event occurred.
During the new outlook period the probability of an elevated energetic
proton flux event >10 MeV
(10+0) is placed at 50%.
An elevated energetic proton flux level greater then (10+0) on 160 meters
and greater then (10-1)
on the medium frequency broadcast band creates noticeably increased winter
time day and year round
night time D layer absorption of medium wave frequencies, especially on high
latitude propagation
paths but it can also negatively impact mid latitudes, depending on the
intensity of the event.
Elevated energetic proton events too small to be categorized as a Polar Cap
Absorption event (PCA)
can still impact high and mid level medium frequency propagation paths in
the form of excessive D
layer absorption. This fact is still stubbornly opposed by some otherwise
very knowledgeable space
weather physicists over dependent on threshold Riometer readings.
((((Note, high latitude medium frequency radio propagation paths can still
be disturbed for days
and up to weeks, following the end of an official >10 MeV (10+0) proton
event.))))
SOLAR FLUX-
During the previous 7 day period the daily solar flux values ranged between
221 and 188.
During the new outlook period the daily solar flux values should range
between approximately 190
and 150.
NOTICE!!! During the outlook period F-1/2 layer propagation openings on 6
meters are improbable.
Occasional auroral propagation is probable, with Sporadic E (Es) and Trans
Equatorial Scatter (TEQ) openings also probable.
During the previous 7 day period the background X-ray flux levels ranged
between B9.6 and B6.5.
Elevated background X-ray flux levels can impact propagation of medium
frequency signals in a
negative manner. Background X-ray flux levels of C2 or greater creates
increased D-layer absorption
of 160 and 120 meter signals and C1 or greater creates increased D-layer
absorption of AM broadcast
band signals.
High solar flux values are generally considered to be detrimental to
propagation of medium
frequency signals both domestic and Trans Atlantic (TA) & Trans Pacific
(TP), as more
absorption can be present via the transmitted signals' two trips through the
D layer at the takeoff
and arrival points.
Most "strong" longer haul medium frequency DX signals in excess of 3000
miles is via the E Valley-F
layer ducting and/or Chordal Hop propagation modes. Therefore high solar
flux values can aid in
long haul medium frequency propagation paths in excess of 3000 miles, as a
high solar flux value
ensures a strong F layer part of the E Valley-F layer duct or Chordal Hop
propagation mechanism.
However high solar activity in the form of increased ionization created by
Ultraviolet and X-Ray
radiation can fill in the E Valley region and interfere with the E Valley-F
layer ducting
mechanism. In a sense the E Valley-F layer duct is closed on one or both
ends of a propagation path
and the transmitted MF RF signal only propagates between the E layer and
land/ocean surface, with a
higher angle and more loss.
SUNSPOT REGIONS/SOLAR FLARES-
During the previous 7 day period six M class solar flares occurred.
The largest was a M2.2 solar flare which occurred at 1449-1504 UTC on
02/09/10.
Recently numbered sunspot region #10114 located at S12W02 which split off
from #10105 contains a
beta-gamma-delta class magnetic signature, harbors energy for medium sized M
class solar flares and
also huge X class solar flares.
Sunspot region #10105 located at S07W18 contains a beta-gamma class magnetic
signature, harbors
energy for medium sized M class solar flares.
During the outlook period I place the chance of a C class solar flare at
100%, an M class at 60%
and an X class at 40%.
An earthward facing C4 or higher class solar flare "can" elevate the proton
flux above 10 MeV
(10+0) and initiate large scale high and mid latitude propagation path
absorption on the AM
broadcast band, 160 and 120 meters, both stateside and DX, as a transfer of
increased density and
RF signal absorption from the day side D layer to night side of the
ionosphere occurs through high
level neutral winds. Unfortunately even smaller C3 solar flares can create
hour to hour and night to
night variations in signal strength on medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths tend to open up
after a significant period of time passes without an elevated energetic
proton event of >10 MeV
(10+0). This fact is still stubbornly opposed by some otherwise very
knowledgeable space weather
physicists over dependent on threshold Riometer readings.
Openings also occur when the solar background x-ray level falls back to or
below C1 for 160 and 120
meters and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
During the previous 7 day period no geo-effective (Earth facing) Coronal
Mass Ejections (CME's)
occurred.
During the previous 7 day period our planet did encounter a Solar Wind
Stream flowing from a
geo-effective (Earth facing) Coronal Hole. The solar stream arrived at 0900
UTC 02/09/11 triggering
a moderate (Kp-6)(G2) ionospheric storm and Visible mid latitude Aurora.
During the new outlook period no geo-effective (Earth facing) Coronal Holes
no Solar Wind Streams
are expected.
During the outlook period the probability of a geo-effective (Earth facing)
Coronal Mass Ejection
(CME) is placed at 50%.
During the outlook period the probability of unsettled (Kp-3) to active
(Kp-4) geomagnetic
conditions is placed at 40%.
During the outlook period the probability of at least a moderate ionospheric
storm (Kp-5)(G1) is
placed at 30%.
During the outlook period the probability of a visible mid latitude Aurora
display is placed at
30%.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
Earth's IMF polarity,
forecasts a positive polarity from 02/09/15-02/09/20.
When the polarity of the IMF is negative a visible mid latitude Aurora
display is likely when a CME
strikes the Earth's magnetic field. When the polarity of the IMF is positive
a visible mid latitude Aurora display is
unlikely as a CME strikes the Earth's magnetic field.
A Coronal Mass Ejection is the name given to an ejection of a large amount
of matter from the Sun's
outer atmosphere or corona. These ejections typically comprise millions of
tons of material in the
form of charged particles, and can be seen because the material reflects
sunlight. When one
of these ejections is directed towards the Earth (or conversely, directly
away from the Earth), it
looks like a roughly circular "halo" surrounding the Sun.
The "Halo CME's" then are those CME's which are more likely to impact the
Earth than those which
are shot out at right angles to the Earth-Sun line. Energetic protons
emitted during CME's play a
major role in increased day time and night-time D-layer absorption of
mediumwave frequencies.
Coronal Mass Ejections were once thought to be completely initiated by solar
flares. However it is
now known that many (CME's) are not associated with Solar Flares. If a (CME)
collides with the
Earth, it can excite a Geomagnetic Storm if the polarity of the IMF has a
negative sign. We must be
vigilant in watching for geoeffective (CME's), in order to not be caught by
surprise with a
seemingly sudden and unexpected Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in
magnetic latitude and
generally begins having a negative impact on high latitude medium frequency
propagation paths. A Kp
index of 5 or higher begins to have a negative impact on high latitude high
frequency shortwave
propagation paths. However at times skewed path propagation conditions can
compensate for high
latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period increased winter like day and year round night
time D layer absorption of
medium frequency signals tied to stratospheric warming should not occur.
Stratospheric warming is a major temperature change of the winter time polar
and middle atmosphere
from the tropopause (where the troposphere transitions into the
stratosphere) to the base (D-layer)
of the ionosphere, lasting for many days at a time and characterized by a
warming of the
stratospheric temperature by some tens of degrees (temperature inversion).
As the stratosphere lies below the ionosphere, which is at mesosphere and
thermosphere height, you
would not expect to see stratospheric warming effect medium frequency
propagation in any way BUT
medium frequency signals do refract off of temperature inversions and
moisture discontinuities and
a temperature inversion is involved with stratospheric warming. So it's
possible that a medium
frequency signal could do any number of things when refracting off of a
temperature inversion, at
any height.
Also stratospheric warming (STRATWARM) has a negative effect on medium
frequency propagation, due
to increasing medium frequency radio wave absorption by the D layer, via
upward propagating
Internal Gravity Waves (IGW).
Also I have observed that stratospheric warming usually coincides with major
jetstream circulation
pattern changes and movement of Arctic air masses from Siberian Russia
across the pole to Canada
and the U.S.
This phenomenon also occurs in southern hemisphere winter but seems to be
less pronounced.
7 DAY FORECAST OUTLOOK-
As we approach the fall/spring equinox propagation conditions will become
more balanced in both
hemispheres. Also as is the norm geomagnetic activity will increase.
Expect good domestic propagation conditions in the northern hemisphere out
to approximately 1050
miles.
Expect very good domestic propagation conditions in the southern hemisphere
out to approximately
1050 miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions in excess of approximately 3000 miles should be fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions in excess of approximately 3000 miles should be good.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions in excess of approximately 3000 miles should be fair
to good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions in excess of approximately 3000 miles should be very
good to very good.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions
in excess of approximately 3000 miles should be very good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions
in excess of approximately 3000 miles should be very good.
There will be "moderate to high" lightning induced QRN levels in mid and low
latitude areas of the
northern hemisphere tied to warm season thunderstorms and tropical systems
during the forecast
period.
Occasional lightning induced QRN will occur across the mid and low latitude
areas of the southern
hemisphere, with an endless series of winter time approaching cold fronts
and surface
extra-tropical low pressure systems.
High to moderate lightning induced QRN will continue in the vicinity of the
tropical ITCZ and
across equatorial regions.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-23
Published
1:00 PM EDT 02/09/08 For 02/09/09-02/09/15.
Though this
outlook is aimed primarily at medium frequencies, virtually all
the following
propagation data is applicable to HF frequencies.
This 7 day medium
frequency (300-3000 kc) propagation outlook and other
solar, space weather
and propagation data can be found on my website at
http://www.kn4lf.com/kn4lf5.htm
.
Due to the international scope of the Amateur Radio/SWL radio community
I
have adopted the date format of yy/mm/dd.
REVIEW-
The week of
02/09/02-02/09/08 was relatively quiet considering that we are
approaching
the Fall/Spring Equinox.
ENERGETIC PROTON FLUX-
During the
previous seven day period one >10 MeV (10+0) energetic proton
event
occurred. It began at 0455 UTC on 02/09/07 and ended at 0230 UTC on
02/09/08.
At it's peak it reached approximately 210 pfu. (10+2).
Originally I
thought that the source of this elevated energetic proton event
was old
sunspot group #10069 (now renumbered as 10105) which actually
arrived around
the Sun's eastern limb early this morning. However it may
have been
associated with the a filament eruption just east of sunspot
region #10102 at
16:24 UTC triggered a long duration C5.2 solar from solar
region #10102
peaking.
During the previous outlook period I had forecasted the
probability of an
elevated energetic proton flux event >10 MeV
(10+0).
During the new outlook period the probability of an elevated
energetic
proton flux event >10 MeV (10+0) is placed at 60%.
An elevated energetic proton flux level greater then (10+0) on 160 meters
and greater then (10-1) on the medium frequency broadcast band creates
noticeably
increased winter time day and year round night time D layer
absorption of
medium wave frequencies, especially on high latitude
propagation paths but
it can also negatively impact mid latitudes, depending
on the intensity of
the event. Elevated energetic proton events too small to
be categorized as a
Polar Cap Absorption event (PCA) can still impact high
and mid level medium
frequency propagation paths in the form of excessive D
layer absorption.
This fact is still stubbornly opposed by some otherwise
very knowledgeable
space weather physicists over dependent on threshold
Riometer readings.
((((Note, high latitude medium frequency radio propagation
paths can still
be disturbed for days and up to weeks, following the end of
an official >10
MeV (10+0) proton event.))))
SOLAR FLUX-
During the previous 7 day period the daily solar flux values ranged
between
192 and 171.
During the new outlook period the daily solar
flux values should range
between approximately 230 and 180.
NOTICE!!!
During the latter part of the outlook period F-1/2 layer
propagation openings
on 6 meters are possible.
Occasional auroral propagation is probable,
with Sporadic E (Es) and Trans
Equatorial Scatter (TEQ) openings also
probable.
During the previous 7 day period the background X-ray flux
levels ranged
between C1.3 and B6.4.
Elevated background X-ray flux
levels can impact propagation of medium
frequency signals in a negative
manner. Background X-ray flux levels of C2
or greater creates increased
D-layer absorption of 160 and 120 meter signals
and C1 or greater creates
increased D-layer absorption of AM broadcast band
signals.
High solar
flux values are generally considered to be detrimental to
propagation of
medium frequency signals both domestic and Trans Atlantic
(TA) &
Trans Pacific (TP), as more absorption can be present via the
transmitted
signals' two trips through the D layer at the takeoff and
arrival
points.
Most "strong" longer haul medium frequency DX signals in excess
of 3000
miles is via the E Valley-F layer ducting and/or Chordal Hop
propagation
modes. Therefore high solar flux values can aid in long haul
medium
frequency propagation paths in excess of 3000 miles, as a high solar
flux
value ensures a strong F layer part of the E Valley-F layer duct or
Chordal
Hop propagation mechanism.
However high solar activity in the
form of increased ionization created by
Ultraviolet and X-Ray radiation can
fill in the E Valley region and
interfere with the E Valley-F layer ducting
mechanism. In a sense the E
Valley-F layer duct is closed on one or both ends
of a propagation path and
the transmitted MF RF signal only propagates
between the E layer and
land/ocean surface, with a higher angle and more
loss.
SUNSPOT REGIONS/SOLAR FLARES-
During the previous 7
day period the visible sunspot groups were less active
with only two M class
solar flares occurring.
An M1.1 solar flare occurred at 0049 UTC on
02/09/03. and an M1.5 class
solar flare occurred at 0139 UTC on
02/09/08.
Recently numbered sunspot region #10105 at S06 E77 emerged
around the Sun's
eastern limb early today. This is actually previous sunspot
group #10069
which wreaked havoc on last month's space weather conditions.
#10105 has
emerged with a beta-delta class magnetic signature, which harbors
energy for
medium sized M class solar flares and also huge X class solar
flares in
future days.
Fortunately sunspot group #10105 will not be in
Earth facing (geo-effective)
position for a while yet. That means nil chances
of Coronal Mass Ejections
(CME'S) and Geomagnetic Storms from this group.
However it can still produce
planet impacting elevated energetic proton
events.
During the outlook period I place the chance of a C class solar
flare at
100%, an M class at 70% and an X class at 50%.
An earthward
facing C4 or higher class solar flare "can" elevate the proton
flux above 10
MeV (10+0) and initiate large scale high and mid latitude
propagation path
absorption on the AM broadcast band, 160 and 120 meters,
both stateside and
DX, as a transfer of increased density and RF signal
absorption from the day
side D layer to night side of the ionosphere occurs
through high level winds.
Unfortunately even smaller C3 solar flares can
create hour to hour and night
to night variations in signal strength on
medium frequencies.
High and
mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths
tend to open up after a significant period of time passes without an
elevated
energetic proton event of >10 MeV (10+0). This fact is still
stubbornly
opposed by some otherwise very knowledgeable space weather
physicists over
dependent on threshold Riometer readings.
Openings also occur when the
solar background x-ray level falls back to or
below C1 for 160 and 120 meters
and B9 for the AM broadcast band.
CORONAL MASS
EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
During the previous 7 day
period at least one Coronal Mass Ejections (CME's)
was partially
geo-effective (earth facing).
The full halo CME was associated with a
filament eruption just east of solar
region #10102 and also a long duration
C5.2 solar flare event from solar
region #10102, on 02/09/05.
However,
when the shock from this CME struck the IMF yesterday, it's
polarity turned
negative, an ionospheric storm with a Kp of 7 (G3) commenced
and visible mid
latitude Aurora did occur.
During the previous 7 day period our planet
did encounter a solar wind
stream flowing from a geo-effective (Earth facing)
coronal hole. The solar
stream arrived on 02/09/04 triggering a moderate
(Kp-6)(g2) ionospheric
storm.
A solar wind stream from a new
geo-effective (Earth facing) coronal hole
could buffet Earth's Interplanetary
Magnetic Field (IMF) as early as
02/09/10, triggering a minor (Kp-5)(G1) to
moderate (KP-6)(G2)ionospheric
storm.
During the outlook period the
probability of an Earth directed Coronal Mass
Ejection (CME) is placed at
50%.
During the outlook period the probability of unsettled (Kp-3) to
active
(Kp-4) geomagnetic conditions is placed at 80%.
During the
outlook period the probability of at least a moderate ionospheric
storm
(Kp-5)(G1) is placed at 60%.
During the outlook period the probability of
a visible mid latitude Aurora
display is placed at 60%.
The
Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts
Earth's
IMF polarity, forecasts a positive polarity from 02/09/05-02/09/09.
When
the polarity of the IMF is negative a visible mid latitude Aurora
display is
likely when a CME strikes the Earth's magnetic field. When the
polarity of
the IMF is positive a visible mid latitude Aurora display is
unlikely as a
CME strikes the Earth's magnetic field.
A Coronal Mass Ejection is the
name given to an ejection of a large amount
of matter from the Sun's outer
atmosphere or corona. These ejections
typically comprise millions of tons of
material in the form of charged
particles, and can be seen because the
material reflects sunlight. When one
of these ejections is directed towards
the Earth (or conversely, directly
away from the Earth), it looks like a
roughly circular "halo" surrounding
the Sun.
The "Halo CME's" then are
those CME's which are more likely to impact the
Earth than those which are
shot out at right angles to the Earth-Sun line.
Energetic protons emitted
during CME's play a major role in increased day
time and night-time D-layer
absorption of mediumwave frequencies.
Coronal Mass Ejections were once
thought to be completely initiated by solar
flares. However it is now known
that many (CME's) are not associated with
Solar Flares. If a (CME) collides
with the Earth, it can excite a
Geomagnetic Storm if the polarity of the IMF
has a negative sign. We must be
vigilant in watching for geoeffective
(CME's), in order to not be caught by
surprise with a seemingly sudden and
unexpected Geomagnetic Storm.
As the Kp index reaches 3-4, the aurora
oval begins expanding equatorward in
magnetic latitude and
generally
begins having a negative impact on high latitude medium frequency
propagation
paths. A Kp index of 5 or higher begins to have a negative
impact on high
latitude high frequency shortwave propagation paths. However
at times skewed
path propagation conditions can compensate for high latitude
propagation path
auroral absorption.
STRATOSPHERIC WARMING-
During the outlook
period increased winter like day and year round night
time D layer absorption
of medium frequency signals tied to stratospheric wa
rming should not
occur.
Stratospheric warming is a major temperature change of the winter
time polar
and middle atmosphere from the tropopause (where the troposphere
transitions
into the stratosphere) to the base (D-layer) of the ionosphere,
lasting for
many days at a time and characterized by a warming of the
stratospheric
temperature by some tens of degrees (temperature
inversion).
As the stratosphere lies below the ionosphere, which is at
mesosphere and
thermosphere height, you would not expect to see stratospheric
warming
effect medium frequency propagation in any way BUT medium frequency
signals
do refract off of temperature inversions and moisture discontinuities
and a
temperature inversion is involved with stratospheric warming. So
it's
possible that a medium
frequency signal could do any number of things
when refracting off of a
temperature inversion, at any height.
Also
stratospheric warming (STRATWARM) has a negative effect on medium
frequency
propagation, due to increasing medium frequency radio wave
absorption by the
D layer, via upward propagating Internal Gravity Waves
(IGW).
Also I
have observed that stratospheric warming usually coincides with
major
jetstream circulation pattern changes and movement of Arctic air masses
from
Siberian Russia across the pole to Canada and the U.S.
This
phenomenon also occurs in southern hemisphere winter but seems to be
less
pronounced.
7 DAY FORECAST OUTLOOK-
As we approach the
fall/spring equinox propagation conditions will become
more balanced in both
hemispheres. Also as is the norm geomagnetic activity
will
increase.
Expect good domestic propagation conditions in the northern
hemisphere out
to approximately 1050 miles.
Expect very good domestic
propagation conditions in the southern hemisphere
out to approximately 1050
miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP)
Trans Pacific
and cross equatorial propagation conditions in excess of
approximately 3000
miles should be fair.
"High latitude" southern
hemispheric (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions in excess of approximately 3000
miles should be
good.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP)
Trans Pacific
and cross equatorial propagation conditions in excess of
approximately 3000
miles should be fair to good.
"Mid latitude"
southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross
equatorial propagation conditions in excess of approximately 3000
miles
should be very good to very good.
"Low latitude" northern hemisphere
(TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in excess of
approximately 3000 miles should be very
good.
"Low latitude" southern
hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation conditions in
excess of approximately 3000 miles should be very
good.
There will
be "moderate to high" lightning induced QRN levels in mid and low
latitude
areas of the northern hemisphere tied to warm season thunderstorms
and
tropical systems during the forecast period.
Occasional lightning induced
QRN will occur across the mid and low latitude
areas of the southern
hemisphere, with an endless series of winter time
approaching cold fronts and
surface extra-tropical low pressure systems.
High to moderate lightning
induced QRN will continue in the vicinity of the
tropical ITCZ and across
equatorial regions.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-22 Published 1:00 PM EDT 02/09/01 For
02/09/02-02/09/08.
Though this outlook is aimed primarily at medium frequencies, virtually all the following propagation data is applicable to HF frequencies.
This 7 day medium frequency (300-3000 kc) propagation outlook and other solar, space weather and propagation data can be found on my website at http://www.kn4lf.com/kn4lf5.htm .
Due to the international scope of the Amateur Radio/SWL radio community I have adopted the date format of yy/mm/dd.
REVIEW-
The week of 02/08/26-02/09/01 was once again active but quiter then the week of 02/08/19-02/08/25, was probably the busiest of solar cycle 23.
ENERGETIC PROTON FLUX-
During the previous seven day period no >10 MeV (10+0) energetic proton events occurred.
During the outlook period the probability of an elevated energetic proton flux event >10 MeV (10+0) is placed at 40%.
An elevated energetic proton flux level >10 MeV (10+0) creates noticibly increased winter time day and year round night time D layer absorption of medium wave frequencies, especially on high latitude propagation paths but it can also negatively impact mid latitudes, depending on the
intensity of the event. Elevated energetic proton events too small to be categorized as a Polar Cap Absorption event (PCA) can still impact high and mid level medium frequency propagation paths in the form of excessive D layer absorption. This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists over dependent on threshold Riometer readings.
((((Note, high latitude medium frequency radio propagation paths can still be disturbed for days and up to weeks, following the end of an official >10 MeV (10+0) proton event.))))
SOLAR FLUX-
During the previous 7 day period the daily solar flux values ranged between 180 and 160. My forecast called for a range of 175 and 130.
During the outlook period the daily solar flux values should range between approximately 200 and 150.
NOTICE!!! During the outlook period F-1/2 layer propagation openings on 6 meters are not likely.
Occasional auroral propagation is possible, with Sporadic E (Es) and Trans Equatorial Scatter (TEQ) openings probable.
During the previous 7 day period the background X-ray flux levels ranged between C3.5 and B7.4.
Elevated background X-ray flux levels can impact propagation of medium frequency signals in a negative manner. Background X-ray flux levels of C2 or greater creates increased D-layer absorption of 160 and 120 meter signals and C1 or greater creates increased D-layer absorption of AM broadcast band signals.
High solar flux values are generally considered to be detrimental to propagation of medium frequency signals both domestic and Trans Atlantic (TA) & Trans Pacific (TP), as more absorption can be present via the transmitted signals' two trips through the D layer at the takeoff and arrival points.
Most "strong" longer haul medium frequency DX signals in excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high solar flux values can aid in long haul medium frequency propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong F layer part of the E Valley-F layer duct or Chordal Hop propagation mechanism.
However high solar activity in the form of increased ionization created by Ultraviolet and X-Ray radiation can fill in the E Valley region and interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F layer duct is closed on one or both ends of a propagation path and the transmitted MF RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS/SOLAR FLARES-
During the previous 7 day period the visible sunspot groups were less active with six M class solar flares and one X class solar flare occurring.
Recently numbered sunspot region #10095 at N7E51 with it's beta-gamma-delta class magnetic signature, harbors energy for "more" huge geo-effective (Earth facing) X class solar flares in future days.
On 02/08/30 #10095 released an unexpected major X1.6 class solar flare, between 1324 and 1344 UTC.
Fortunately this huge solar flare did not trigger a >10 MeV (10+0) energetic proton event nor a geo-effective (Earth facing) Coronal Mass Ejection (CME).
Sunspot group #10087 at S08W47 with it's beta-gamma class magnetic signature harbors energy for medium sized geo-effective (Earth facing) M class solar flares.
During the outlook period I place the chance of a C class solar flare at 100%, an M class at 70% and an X class at 40%.
An earthward facing C4 or higher class solar flare "can" elevate the proton flux above 10 MeV (10+0) and initiate large scale high and mid latitude propagation path absorption on the AM broadcast band, 160 and 120 meters, both stateside and DX, as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds. Unfortunately even smaller C3 solar flares can create hour to hour and night to night variations in signal strength on medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation paths tend to open up after a significant period of time passes without an elevated energetic proton event of >10 MeV (10+0). This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists over dependent on threshold Riometer readings.
Openings also occur when the solar background x-ray level falls back to or below C1 for 160 and 120 meters and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
During the previous 7 day period no Coronal Mass Ejections (CME's) were partially or totally geo-effective (earth facing).
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts Earth's IMF polarity, forecasts a positive polarity thru 02/09/05.
When the polarity of the IMF is negative a visible mid latitude Aurora display is likely, when a CME strikes the Earth's magnetic field. When the polarity of the IMF is positive, a visible mid latitude Aurora display is unlikely as a CME strikes the Earth's magnetic field.
During the previous 7 day period our planet did encounter a solar wind stream flowing from a geo-effective (Earth facing) coronal hole. The solar stream arrived on 02/08/30 triggering unsettled (Kp-3) to active (Kp-4) geomagnetic conditions.
During the outlook period a coronal hole will continue in a geo-effective position.
During the outlook period the probability of an Earth directed Coronal Mass Ejection (CME) is placed at 30%.
During the outlook period the probability of unsettled (Kp-3) to active (Kp-4) geomagnetic conditions is placed at 70%.
During the outlook period the probability of an ionospheric storm (Kp-5) is placed at 30%.
During the outlook period the probability of a visible mid latitude Aurora display is placed at
20%.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in magnetic latitude and
generally begins having a negative impact on high latitude medium frequency propagation paths. A Kp index of 5 or higher begins to have a negative impact on high latitude high frequency shortwave propagation paths. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period increased winter like day and year round night time D layer absorption of medium frequency signals tied to stratospheric warming should not occur.
Stratospheric warming is a major temperature change of the winter time polar and middle atmosphere from the tropopause (where the troposphere transitions into the stratosphere) to the base (D-layer) of the ionosphere, lasting for many days at a time and characterized by a warming of the stratospheric temperature by some tens of degrees (temperature inversion).
As the stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you would not expect to see stratospheric warming effect medium frequency propagation in any way BUT medium frequency signals do refract off of temperature inversions and moisture discontinuities and a temperature inversion is involved with stratospheric warming. So it's possible that a medium
frequency signal could do any number of things when refracting off of a temperature inversion, at any height.
Also stratospheric warming (STRATWARM) has a negative effect on medium frequency propagation, due to increasing medium frequency radio wave absorption by the D layer, via upward propagating Internal Gravity Waves (IGW).
Also I have observed that stratospheric warming usually coincides with major jetstream circulation pattern changes and movement of Arctic air masses from Siberian Russia across the pole to Canada and the U.S.
A similar pattern also occurs over the southern hemisphere but seems to be less pronounced.
7 DAY FORECAST OUTLOOK-
As we approach the fall/spring equinox propagation conditions will become more balanced in both hemispheres. Also as is the norm geomagnetic activity will increase.
Expect good domestic propagation conditions in the northern hemisphere out to approximately 1050 miles.
Expect very good domestic propagation conditions in the southern hemisphere out to approximately 1050 miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be good.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be very good.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in excess of approximately 3000 miles should be good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in excess of approximately 3000 miles should be very good.
There will be "moderate to high" lightning induced QRN levels in mid and low latitude areas of the northern hemisphere tied to warm season thunderstorms and tropical systems during the forecast period.
Occasional lightning induced QRN will occur across the mid and low latitude areas of the southern hemisphere, with an endless series of winter time approaching cold fronts and surface extra-tropical low pressure systems.
High to moderate lightning induced QRN will continue in the vicinity of the tropical ITCZ and across equatorial regions.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook Update #2002-21A
Published at 11:00 AM EDT 02/08/30.
Sunspot group #10095 at N07E76, which is newly arrived around the east limb of the sun with it's beta-gamma-delta class magnetic signature, released an unexpected major X1.6 solar flare, between 1324 and 1344 UTC on 02/08/30.
Fortunately this huge solar flare appears to not have triggered a >10 MeV (10+0) energetic proton event nor a geo-effective (Earth facing) Coronal Mass Ejection (CME).
Sunspot group #10087 at S08W20 with it's beta-gamma-delta class magnetic signature and newly arrived #10094 at S17E67 with it's beta-delta class magnetic signature both both harbor energy for medium geo-effective (Earth facing) M class solar flares and also possibly huge X class solar
flares in future days.
In outlook #2002-20 I had placed the probability of an elevated energetic proton flux event >10 MeV (10+0) at 50%.
I had also placed the chance of a C class solar flare at 100%, an M class at 80% and an X class at 40%.
An elevated energetic proton flux level >10 MeV (10+0) creates increased winter time day and year round night time D layer absorption of medium wave frequencies, especially on high latitude propagation paths but it can also negatively impact mid latitudes, depending on the intensity of the event. Elevated energetic proton events too small to be categorized as a Polar Cap Absorption event (PCA)can still impact high and mid level medium frequency propagation paths in the form of excessive D layer absorption. This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists over dependent on threshold Riometer readings. ((((Note, high latitude medium frequency radio propagation paths can still be disturbed for days and up to weeks, following the end of an official >10 MeV (10+0) proton event.))))
A new coronal hole is in a geo-effective position (Earth facing), and should create unsettled (Kp-3) to active (Kp-4) geomagnetic conditions by 02/09/01-02.
In outlook #2002-20 I had placed the probability of an ionospheric storm at 80%.
I had also placed the probability of a visible mid latitude Aurora display at 80%.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which predicts Earth's IMF polarity, is forecasting a
negative polarity thru 02/09/02. When the polarity of the IMF is negative a visible mid latitude Aurora display is likely as a CME strikes the Earth's magnetic field.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in magnetic latitude and
generally begins having a negative impact on high latitude medium frequency propagation paths. A Kp index of 5 or higher begins to have a negative impact on high latitude high frequency shortwave propagation paths. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
-----
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-21 Published 12:00
AM EDT 02/08/26 For 02/08/26-02/09/01.
Though this outlook is aimed
primarily at medium frequencies, virtually all
the following propagation data
is applicable to HF frequencies.
This 7 day medium frequency (300-3000
kc) propagation outlook and other
solar, space weather and
propagation
data can be found on my website at
http://www.kn4lf.com/kn4lf5.htm
.
Due to the international scope of the amateur/SWL radio community I
have
adopted the date format of yy/mm/dd.
The week of
02/08/19-02/08/25 was probably the busiest of solar cycle
23.
ENERGETIC PROTON FLUX-
During the previous seven day
period five >10 MeV (10+0) energetic proton
events occurred. Four
were
minor (doesn't take much of one to foul of the medium waves though) and
one
was major, which
started at 0130 UTC on 02/08/24. It peaked at (10+3) 317 pfu
at 0835 UTC on
02/08/24. This major
event was tied to the X3 class solar
flare emitted from sunspot region
#10069, as it crossed over
the western
limb of the sun.
During the outlook period the probability of an elevated
energetic proton
flux event >10 MeV (10+0)
is placed at 50%.
An
elevated proton flux level >10 MeV (10+0) creates increased winter
time
day and year round night
time D layer absorption of medium wave
frequencies, especially on high
latitude propagation paths
but it can also
negatively impact mid latitudes, depending on the intensity
of the event.
Elevated
energetic proton events too small to be categorized as a Polar
Cap
Absorption event (PCA) can still
impact high and mid level medium
frequency propagation paths in the form of
excessive D layer
absorption.
This fact is still stubbornly opposed by some otherwise very
knowledgeable
space
weather physicists over dependent on threshold Riometer readings.
((((Note,
high latitude medium
frequency radio propagation paths can still
be disturbed for days and up to
weeks, following the
end of an official
>10 MeV (10+0) proton event.))))
SOLAR FLUX-
During the
previous 7 day period the daily solar flux values ranged between
166 and
244.
During the outlook period the daily solar flux values should range
between
approximately 130 and
175.
NOTICE!!! During the
outlook period F-1/2 layer propagation openings on 6
meters are not
likely.
Also occasional auroral propagation is possible, with
Sporadic E (Es) and
Trans Equatorial Scatter
(TEQ) openings are
probable.
During the previous 7 day period the background X-ray flux
levels ranged
between B8.9 and C2.4.
Background X-ray flux levels can
impact medium frequency signals in a
negative manner. Background
X-ray
flux levels of C2 or greater creates increased D-layer absorption of
160 and
120 meter
signals and C1 or greater creates increased D-layer absorption of
AM
broadcast band signals.
High solar flux values are generally considered
to be detrimental to
propagation of medium
frequency signals both domestic
and Trans Atlantic (TA) & Trans Pacific
(TP), as more
absorption
can be present via the transmitted signals' two trips through the
D layer at
the takeoff
and arrival points.
Most "strong" longer haul medium
frequency DX signals in excess of 3000
miles is via the E Valley-F
layer
ducting and/or Chordal Hop propagation modes. Therefore high solar
flux
values can aid in
long haul medium frequency propagation paths in excess of
3000 miles, as a
high solar flux value
ensures a strong F layer part of
the E Valley-F layer duct or Chordal Hop
propagation mechanism.
However
high solar activity in the form of increased ionization created
by
Ultraviolet and X-Ray
radiation can fill in the E Valley region and
interfere with the E Valley-F
layer ducting
mechanism. In a sense the E
Valley-F layer duct is closed on one or both
ends of a propagation
path
and the transmitted MF RF signal only propagates between the E layer
and
land/ocean surface, with a
higher angle and more
loss.
SUNSPOT REGIONS/SOLAR FLARES-
During the previous 7 day
period the visible sunspot groups were very
active, with 19 M class
solar
flares and two X class occurring. Also unfortunately at least four (I
lost
count) Coronal Mass
Ejections (CME's) were partially or totally
geo-effective (earth facing).
Sunspot group #10069 has rotated around the
SW limb of the sun. This very
active group was
responsible for nearly all
of the M and X class solar flares and will
probably hold together and be
a
trouble maker again in September, as it rotates around the NE limb of
the
sun.
Sunspot group #10083 at S18W71 contains a beta-delta magnetic
configuration
and #10087 at S08E06 a
beta-gamma-delta. Both harbor energy
for medium geo-effective (Earth facing)
M class solar flares
and also
possibly huge X class solar flares in future days.
During the outlook
period I place the chance of a C class solar flare at
100%, an M class at
80%
and an X class at 40%.
An earthward facing C4 or higher class
solar flare can elevate the proton
flux above 10 MeV (10+0)
and initiate
large scale high and mid latitude propagation path absorption
on the AM
broadcast
band, 160 and 120 meters, both stateside and DX, as a transfer of
increased
density and RF signal
absorption from the day side D layer to
night side of the ionosphere occurs
through high level
neutral winds.
Unfortunately even smaller C3 solar flares can create hour to
hour and night
to
night variations in signal strength on medium frequencies.
High and
mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation
paths
tend to open up
after a significant period of time passes without an elevated
energetic
proton event of >10 MeV
(10+0). This fact is still stubbornly
opposed by some otherwise very
knowledgeable space weather
physicists over
dependent on threshold Riometer readings.
Openings also occur when the solar
background x-ray level falls back to or
below C1 for 160 and 120
meters
and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC
STORMS/VISIBLE AURORA-
During the previous 7 day period at least four (I
lost count) Coronal Mass
Ejections (CME's) were
partially or totally
geo-effective (earth facing).
During the outlook period the probability
of an Earth directed Coronal Mass
Ejection (CME) is
placed at
80%.
The Wang-Sheeley Interplanetary Magnetic Field (IMF) Model which
predicts
Earth's IMF polarity,
calls a continued negative polarity thru
02/09/02.
When the polarity of the IMF is negative a visible mid latitude
Aurora
display is likely as a CME strikes the Earth's magnetic
field.
During the previous 7 day period our planet did encounter a solar
wind
stream flowing from a geo-effective (Earth facing) coronal
hole.
A new coronal hole will be in a geo-effective position (Earth
facing) by the
end of this week, creating unsettled (Kp-3) to active (Kp-4)
geomagnetic
conditions.
During the outlook period the probability of
an ionospheric storm is placed
at 80%.
During the outlook period the
probability of a visible mid latitude Aurora
display is placed at
80%.
As the Kp index reaches 3-4, the aurora oval begins expanding
equatorward in
magnetic latitude and
generally begins having a negative
impact on high latitude medium frequency
propagation paths. A Kp
index of
5 or higher begins to have a negative impact on high latitude high
frequency
shortwave
propagation paths. However at times skewed path propagation
conditions can
compensate for high
latitude propagation path auroral
absorption.
STRATOSPHERIC WARMING-
During the outlook period
increased winter like day and year round night
time D layer absorption
of
medium frequency signals tied to stratospheric warming should not
occur.
Stratospheric warming is a major temperature change of the winter time
polar
and middle atmosphere from the tropopause (where the troposphere
transitions
into the stratosphere) to the base (D-layer) of the ionosphere,
lasting for
many days at a time and characterized by a warming of
the
stratospheric temperature by some tens of degrees (temperature
inversion).
As the stratosphere lies below the ionosphere, which is at
mesosphere and
thermosphere height, you
would not expect to see
stratospheric warming effect medium frequency
propagation in any way
BUT
medium frequency signals do refract off of temperature inversions
and
moisture discontinuities and
a temperature inversion is involved with
stratospheric warming. So it's
possible that a medium
frequency signal
could do any number of things when refracting off of a
temperature inversion,
at
any height.
Also stratospheric warming (STRATWARM) has a negative
effect on medium
frequency propagation, due
to increasing medium frequency
radio wave absorption by the D layer, via
upward propagating
Internal
Gravity Waves (IGW).
Also I have observed that stratospheric warming
usually coincides with major
jetstream circulation
pattern changes and
movement of Arctic air masses from Siberian Russia
across the pole to
Canada
and the U.S.
7 DAY FORECAST OUTLOOK-
Expect fair,
then becoming good domestic propagation conditions in the
northern hemisphere
out to
approximately 1050 miles.
Expect good, then becoming very good
domestic propagation conditions in the
southern hemisphere out
to
approximately 1050 miles.
"High latitude" northern hemispheric (TA) Trans
Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions
in excess of approximately 3000 miles should be poor,
then becoming
fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP)
Trans Pacific
and cross equatorial
propagation conditions in excess of
approximately 3000 miles should be fair,
then becoming good.
"Mid
latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and
cross equatorial
propagation conditions in excess of approximately 3000 miles
should be fair,
then becoming good.
"Mid latitude" southern hemisphere
(TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation
conditions in excess of approximately 3000 miles should be good,
then
becoming very
good.
"Low latitude" northern hemisphere (TA) Trans
Atlantic, (TP) Trans Pacific
propagation conditions
in excess of
approximately 3000 miles should be fair, then becoming good.
"Low
latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans
Pacific
propagation conditions
in excess of approximately 3000 miles
should be good, then becoming very
good.
There will be "moderate to
high" lightning induced QRN levels in mid and low
latitude areas of
the
northern hemisphere tied to warm season thunderstorms and tropical
systems
during the forecast
period.
Occasional lightning induced
QRN will occur across the mid and low latitude
areas of the
southern
hemisphere, with an endless series of winter time approaching cold
fronts
and surface
extra-tropical low pressure systems.
High to
moderate lightning induced QRN will continue in the vicinity of the
tropical
ITCZ and
across equatorial regions.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook Update #2002-20B Updated 11:00 AM EDT 02/08/22.
Though this outlook is aimed primarily at medium frequencies, virtually all the following propagation data is applicable to HF frequencies.
This 7 day medium frequency (300-3000 kc) propagation outlook and other solar, space weather and
more propagation data can be found on and you can also sign up for the e-list version of this MF propasgation outlook at:
http://www.kn4lf.com/kn4lf5.htm .
Due to the international scope of the amateur/SWL radio community I have adopted the date format of yy/mm/dd.
Sunspot group #10069 with it's delta class magnetic signature, released yet another major solar flare, this time an M5.4 between 0149 and 0224 UTC on 02/08/22.
Unfortunately this flare triggered a >10 MeV (10+0) energetic proton event and also released at least a partially geo-effective (Earth facing) Coronal Mass Ejection (CME). This CME may trigger yet another Ionospheric Storm and visible Aurora display within 2-3 days.
In outlook #2002-20 we placed the probability of an elevated energetic proton flux event >10 MeV (10+0) at placed at 80%.
Check out this link which takes you to the latest energetic proton flux at:
http://www.kn4lf.com/082202protonflux.gif
An elevated proton flux level >10 MeV (10+0) creates increased winter time day and year round night time D layer absorption of medium wave frequencies, especially on high latitude propagation paths but it can also negatively impact mid latitudes, depending on the intensity of the
event. Elevated energetic proton events too small to be categorized as a Polar Cap Absorption event (PCA) can still impact high and mid level medium frequency propagation paths in the form of excessive D layer absorption. This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists over dependent on threshold Riometer readings. ((((Note, high latitude medium frequency radio propagation paths can still be disturbed for days and up to weeks, following the end of an official >10 MeV (10+0) proton event.))))
-----
KN4LF 7 Day Medium Frequency Radio Propagation Outlook Update #2002-20A Updated
11:00 AM EDT 02/08/21.
As forecasted in outlook #2002-20, incredibly huge
sunspot group #10069, with it's multiple delta class magnetic signature,
released an enourmous X1.0 class solar flare between 0529-0549 UTC on
02/08/21.
A major ionospheric storm with a peak Kp of 7 so far is
underway.
-----
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-20 Published 12:00 PM EDT 02/08/18 For 02/08/19-02/08/25.
Though this outlook is aimed primarily at medium frequencies, virtually all the following propagation data is applicable to HF frequencies.
This 7 day medium frequency (300-3000 kc) propagation outlook and other solar, space weather and
Propagation data can be found on my website at http://www.kn4lf.com/kn4lf5.htm .
Due to the international scope of the amateur/SWL radio community I have adopted the date format of yy/mm/dd.
ENERGETIC PROTON FLUX-
During the previous seven day period one minor >10 MeV (10+0) energetic proton events occurred. It began during the evening of 02/08/16 and ended early morning 02/08/18. It was probably tied to solar region #10078, which produced an M1 at 2333 UTC on 02/08/16.
During the outlook period the probability of an elevated energetic proton flux event >10 MeV (10+0) is placed at 80%.
An elevated proton flux level >10 MeV (10+0) creates increased winter time day and year round night time D layer absorption of medium wave frequencies, especially on high latitude propagation paths but it can also negatively impact mid latitudes, depending on the intensity of the event. Elevated energetic proton events too small to be categorized as a Polar Cap Absorption event (PCA) can still impact high and mid level medium frequency propagation paths in the form of excessive D layer absorption. This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists over dependent on threshold Riometer readings. ((((Note, high latitude medium frequency radio propagation paths can still be disturbed for days and up to weeks, following the end of an official >10 MeV (10+0) proton event.))))
SOLAR FLUX-
During the previous 7 day period the daily solar flux values ranged between 241 and 179.
During the outlook period the daily solar flux values should range between approximately 275 and 195.
NOTICE!!! During the outlook period F-1/2layer propagation openings on 6 meters are possible but mainly on north and south routes!
Also occasional auroral propagation is possible, with Sporadic E (Es) and Trans Equatorial Scatter (TEQ) openings are increasingly probable.
During the previous 7 day period the background X-ray flux levels ranged between B8.9 and C2.4.
Background X-ray flux levels can impact medium frequency signals in a negative manner. Background X-ray flux levels of C2 or greater creates increased D-layer absorption of 160 and 120 meter signals and C1 or greater creates increased D-layer absorption of AM broadcast band signals.
High solar flux values are generally considered to be detrimental to propagation of medium frequency signals both domestic and Trans Atlantic (TA) & Trans Pacific (TP), as more absorption can be present via the transmitted signals' two trips through the D layer at the takeoff and arrival points.
Most "strong" longer haul medium frequency DX signals in excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high solar flux values can aid in long haul medium frequency propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong F layer part of the E Valley-F layer duct or Chordal Hop propagation mechanism.
However high solar activity in the form of increased ionization created by Ultraviolet and X-Ray radiation can fill in the E Valley region and interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F layer duct is closed on one or both ends of a propagation path and the transmitted MF RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS/SOLAR FLARES-
During the previous 7 day period the visible sunspot groups were very active, with 11 M class solar flares occurring. Also unfortunately three Coronal Mass Ejections (CME's) were geo-effective (earth facing).
Sunspot group #100069 at S07W03 is incredibly huge, at many times the size of Earth and very magnetically complex. This sunspot group continues to grow and may become the largest sunspot group of cycle 23. It is also capable of geo-effective (Earth facing) and HUGE (R4) X10+ class solar flares, a withering coronal mass ejection, ionospheric storm and visible aurora down to 28 deg. N/S.
Fast growing sunspot group #10079 at S21E18 contains a beta-gamma magnetic configuration that harbor energy for medium geo-effective (Earth facing) M class solar flares.
During the outlook period I place the chance of a C class solar flare at 100%, an M class at 80% and an X class at 40%.
An earthward facing C4 or higher class solar flare can elevate the proton flux above 10 MeV (10+0) and initiate large scale high and mid latitude propagation path absorption on the AM broadcast band, 160 and 120 meters, both stateside and DX, as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level
neutral winds. Unfortunately even smaller C3 solar flares can create hour to hour and night to night variations in signal strength on medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation paths tend to open up after a significant period of time passes without an elevated energetic proton event of >10 MeV (10+0). This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists over dependent on threshold Riometer readings.
Openings also occur when the solar background x-ray level falls back to or below C1 for 160 and 120 meters and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
Solar region #10069 was the source of a medium size M5.2 class long duration solar flare event, peaking at 12:32 UTC on 02/08/16. A strong type II radio sweep was recorded and a full halo Coronal Mass Ejection (CME) was observed in LASCO C3 within an hour after the event.
The CME will impact Earth, most likely sometime during the first half of August 18 and cause active to major storm levels.
During the previous 7 day period one minor partially geo-effective (Earth facing) Coronal Mass Ejection (CME) affected our planet. A weak CME swept past our planet at 02/08/16, creating a minor ionospheric storm with a Kp of 4-5. High and mid latitude visible aurora displays did not occur.
During the outlook period the probability of an Earth directed Coronal Mass Ejection (CME) is placed at 100%.
The Wang-Sheeley Model Interplanetary Magnetic Field (IMF) Polarity at Earth prediction is for a continued negative polarity thru 02/08/12, then shift to positive from 02/08/13-16. When the polarity of the IMF is negative a visible mid latitude Aurora display is likely as a CME strikes the Earth's magnetic field.
During the outlook period the probability of an ionospheric storm is placed at 80%.
During the outlook period the probability of a visible mid latitude Aurora display is placed at 80%.
As the Kp index reaches 3-4, the aurora oval begins expanding equatorward in magnetic latitude and
generally begins having a negative impact on high latitude medium frequency propagation paths. A Kp index of 5 or higher begins to have a negative impact on high latitude high frequency shortwave propagation paths. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
During the previous 7 day period our planet did encounter a solar wind stream flowing from a geo-effective (Earth facing) coronal hole.
No coronal holes are in a geo-effective (Earth facing) position at this time and no significant sizes coronal hole are expected.
STRATOSPHERIC WARMING-
During the outlook period increased winter like day and year round night time D layer absorption of medium frequency signals tied to stratospheric warming should not occur.
Stratospheric warming is a major temperature change of the winter time polar and middle atmosphere from the tropopause (where the troposphere transitions into the stratosphere) to the base (D-layer) of the ionosphere, lasting for many days at a time and characterized by a warming of the stratospheric temperature by some tens of degrees (temperature inversion).
As the stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you would not expect to see stratospheric warming effect medium frequency propagation in any way BUT medium frequency signals do refract off of temperature inversions and moisture discontinuities and a temperature inversion is involved with stratospheric warming. So it's possible that a medium
frequency signal could do any number of things when refracting off of a temperature inversion, at any height.
Also stratospheric warming (STRATWARM) has a negative effect on medium frequency propagation, due to increasing medium frequency radio wave absorption by the D layer, via upward propagating Internal Gravity Waves (IGW).
Also I have observed that stratospheric warming usually coincides with major jetstream circulation pattern changes and movement of Arctic air masses from Siberian Russia across the pole to Canada and the U.S.
7 DAY FORECAST OUTLOOK-
Expect fair domestic propagation conditions in the northern hemisphere out to approximately 1050 miles.
Expect good domestic propagation conditions in the southern hemisphere out to
approximately 1050 miles.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be poor.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be fair.
"Mid latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be fair.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be good.
"Low latitude" northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in excess of approximately 3000 miles should be fair to good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in excess of approximately 3000 miles should be good.
There will be "moderate to high" lightning induced QRN levels in mid and low latitude areas of the northern hemisphere tied to warm season thunderstorms and tropical systems during the forecast period.
Occasional lightning induced QRN will occur across the mid and low latitude areas of the southern hemisphere, with an endless series of winter time approaching cold fronts and surface extra-tropical low pressure systems.
High to moderate lightning induced QRN will continue in the vicinity of the tropical ITCZ and across equatorial regions.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook Update
#2002-19D
issued 7:00 PM EDT 02/08/16.
A minor Ionospheric Storm with
a peak Kp of 5 has now ended.
A weak >10 MeV (10+0) energetic proton
event began anew at 2345 UTC on
02/08/16, probably produced by solar region
#10078 at S13W39, which produced
an M1 at 2333 UTC on 02/08/16.
A
>10 MeV (10+0) energetic proton event is detrimental to medium
frequency
propagation, as D-layer absorption of signals increase.
Huge
sunspot group #10069 with it's multiple delta class magnetic
signature
continues to be capable of enormous X class solar
flares.
The largest solar flare in the past 24 hours was an M5.2, which
occurred at
1159 UTC on 02/08/16 and was produced by solar region
#10069.
Unfortunately this eruption hurled an apparent geo-effective
(earth facing)
Coronal Mass Ejection (CME). This CME should impact Earth on
02/08/18 +/_ 12
hours.
As the CME from solar region #10069 arrives,
expect at least a minor (Kp=5)
to moderate (Kp=6) but possibly strong (Kp=7)
Ionospheric Storm.
If the Interplanetary Magnetic Field (IMF) polarity
continues with a
negative polarity, a visible mid latitude Aurora display is
likely.
As the Kp index
reaches 3-4, the aurora oval begins expanding equatorward in magnetic
latitude and generally begins having a negative impact on high latitude
medium frequency propagation paths. A Kp index of 5 or higher begins to have
a negative impact on high latitude high frequency shortwave propagation
paths. However at times skewed path propagation conditions can compensate for
high latitude propagation path auroral absorption.
-----
KN4LF 7 Day Medium Frequency Radio Propagation Outlook Update
#2002-19C
Updated 7:00 AM EDT 02/08/16.
A website based version of
this outlook can be found at: KN4LF Daily Solar
Space Weather Geomagnetic
Data Plus
MF Propagation Outlook: http://www.kn4lf.com/kn4lf5.htm
.
A minor Ionospheric Storm with a Kp of 5 is still occurring.
A
weak >10 MeV (10+0) energetic proton event began at 1245 UTC on
02/08/14
and ended at 1825 UTC on 02/08/14.
A >10 MeV (10+0)
energetic proton event is detrimental to medium frequency
propagation, as
D-layer absorption of signals increase.
As forecasted, since 02/08/13
four M class solar flares have occurred, the
largest at M2.4 on 02/08/14 at
0154 UTC.
Also as forecasted, huge sunspot group #10069 located at S07E24
has
developed a delta class magnetic structure and is now capable of enormous
X
class solar flares.
At this moment sunspot group #10069 is not yet
geo-effective (earth facing)
but A >10 MeV (10+0) energetic proton event
is possible.
In future days a Coronal Mass Ejection (CME) and an
ionospheric storm, with
visible mid latitude aurora display is possible, in
association with sunspot
group #10069.
Stay tuned for more info.
-----
KN4LF 7 Day Medium Frequency Radio Propagation Outlook Update #2002-19B Updated 8:00 AM EDT 02/08/14
In a recent development an Flux M 2.4 solar flare occurred at 0154 UTC on 02/08/14.
Unfortunately this flared was followed shortly thereafter with an associated elevated energetic proton flux event >10 MeV (10+0). A >10 MeV proton event is detrimental to medium frequency propagation, as D-layer absorpion of signals increase.
I don't know at this moment if a geo-effective coronal mass ejection (CME) occurred and whether an ionospheric storm will commence, as well as a visible mid latitude aurora display. Stay tuned for more info.
-----
KN4LF 7 Day Medium Frequency Radio Propagation Outlook Update #2002-19A Updated 6:00 PM EDT 02/08/12
In a recent development sunspot region 10069 at S08E77 has developed rapidly and now contains a beta-gamma-delta magnetic structure. This poses a threat for near geo-effective (earth facing) medium size M class solar flares and also a chance of enourmous X class solar flares and associated elevated energetic proton flux events >10 MeV (10+0). A >10 MeV proton event is detrimental to medium frequency propagation, as D-layer absorpion of signals increase.
As the new sunspot group is not in a geo-effective position (earth facing), coronal mass ejections (CMEÂ’s), ionospheric storms and visible mid latitude aurora displays are unlikely.
Fortunately though the background X-ray flux continues low and is currently at B8.5, which is condusive to good propagation conditions on the AM bradcast band 160 and 120 meters.
-----
KN4LF 7 Day Medium Frequency Radio Propagation Outlook Update #2002-19A Updated 6:00 PM EDT 02/08/12
In a recent development sunspot region 10069 at S08E77 has developed
rapidly and now contains a beta-gamma-delta magnetic structure. This
poses a threat for near geo-effective (earth facing) medium size M class
solar flares and also a chance of enourmous X class solar flares and
associated elevated energetic proton flux events >10 MeV (10+0). A >10
MeV proton event is detrimental to medium frequency propagation, as
D-layer absorpion of signals increase.
As the new sunspot group is not in a geo-effective position (earth
facing), coronal mass ejections (CMEÂ’s), ionospheric storms and visible
mid latitude aurora displays are unlikely.
Fortunately though the background X-ray flux continues low and is
currently at B8.5, which is condusive to good propagation conditions on
the AM bradcast band 160 and 120 meters.
-----
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-19
Published
2:00 PM EDT 02/08/11 For 02/08/12-02/08/18.
Though this
outlook is aimed primarily at medium frequencies, it is also
applicable to HF
frequencies.
This 7 day medium frequency (300-3000 kc) propagation
outlook and other
solar, space weather and ionospheric propagation data can
be found on my
website at http://www.kn4lf.com/kn4lf5.htm . You
can also sign up for the
email version of this propagation outlook at the
same URL.
Due to the international scope of the amateur/SWL radio
community I have
adopted the date format of
yy/mm/dd.
REVIEW-
The past seven day period of
02/08/05-02/08/11 has been much quieter then
the previous seven day period.
Overall geomagnetic activity tends to drop in
frequency as we approach the
Spring/Fall equinox.
ENERGETIC PROTON FLUX-
During the
previous seven day period no >10 MeV (10+0) energetic proton
events
occurred.
During the outlook period the probability of an elevated
energetic proton
flux event >10 MeV (10+0) is placed at 20%.
An
elevated proton flux level >10 MeV (10+0) creates increased winter
time
day and year round night time D layer absorption of medium wave
frequencies,
especially on high latitude propagation paths but it can also
negatively
impact mid latitudes, depending on the intensity of the event.
Elevated
energetic proton events too small to be categorized as a Polar
Cap
Absorption event (PCA) can still impact high and mid level medium
frequency
propagation paths in the form of excessive D layer absorption. This
fact is
still stubbornly opposed by some otherwise very knowledgeable space
weather
physicists over dependent on threshold Riometer readings. ((((Note,
high
latitude medium frequency radio propagation paths can still be disturbed
for
days and up to weeks, following the end of an official >10 MeV (10+0)
proton
event.))))
SOLAR FLUX-
During the previous 7 day
period the daily solar flux values ranged between
150 and 135.
During
the outlook period the daily solar flux values should range
between
approximately 190 and 145.
During the previous 7 day period
the background X-ray flux levels ranged
between B5.5 and
B9.5.
Background X-ray flux levels can impact medium frequency signals in
a
negative manner. Background X-ray flux levels of C2 or greater
creates
increased D-layer absorption of 160 and 120 meter signals and C1 or
greater
creates increased D-layer absorption of AM broadcast band
signals.
Unfortunately there will be no important F2 layer propagation
openings on 6
meters during the outlook period due to relatively low daily
solar flux
values and normal summer season depression of F2 ionization levels
in the
northern hemisphere.
However occasional auroral propagation is
possible, with Sporadic E (Es) and
Trans Equatorial Scatter (TEQ) openings
are increasingly probable.
High solar flux values are generally
considered to be detrimental to
propagation of medium frequency signals both
domestic and Trans Atlantic
(TA) & Trans Pacific (TP), as more
absorption can be present via the
transmitted signals' two trips through the
D layer at the takeoff and
arrival points.
Most "strong" longer haul
medium frequency DX signals in excess of 3000
miles is via the E Valley-F
layer ducting and/or Chordal Hop propagation
modes. Therefore high solar flux
values can aid in long haul medium
frequency propagation paths in excess of
3000 miles, as a high solar flux
value ensures a strong F layer part of the E
Valley-F layer duct or Chordal
Hop propagation mechanism.
However high
solar activity in the form of increased ionization created by
Ultraviolet and
X-Ray radiation can fill in the E Valley region and
interfere with the E
Valley-F layer ducting mechanism. In a sense the E
Valley-F layer duct is
closed on one or both ends of a propagation path and
the transmitted MF RF
signal only propagates between the E layer and
land/ocean surface, with a
higher angle and more loss.
SUNSPOT REGIONS/SOLAR
FLARES-
During the previous 7 day period the visible sunspot groups were
less
active, with only two M1 class solar flares occurring. Fortunately
any/all
attendant Coronal Mass Ejections (CME's) were mostly non
geo-effective
(earth facing).
Sunspot group number 10061 contains
beta-gamma magnetic configurations that
harbor energy for medium
geo-effective (Earth facing) M class solar flares.
During the outlook
period I place the chance of a C class solar flare at
100%, an M class at 40%
and an X class at 05%.
An earthward facing C4 or higher class solar flare
can elevate the proton
flux above 10 MeV (10+0) and initiate large scale high
and mid latitude
propagation path absorption on the AM broadcast band, 160
and 120 meters,
both stateside and DX, as a transfer of increased density and
RF signal
absorption from the day side D layer to night side of the
ionosphere occurs
through high level
neutral winds. Unfortunately even
smaller C3 solar flares can create hour to
hour and night to night variations
in signal strength on medium frequencies.
High and mid latitude Trans
Atlantic (TA) and Trans Pacific (TP) propagation
paths tend to open up after
a significant period of time passes without an
elevated energetic proton
event of >10 MeV (10+0). This fact is still
stubbornly opposed by some
otherwise very knowledgeable space weather
physicists over dependent on
threshold Riometer readings.
Openings also occur when the solar
background x-ray level falls back to or
below C1 for 160 and 120 meters and
B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC
STORMS/VISIBLE AURORA-
During the previous 7 day period one minor
partially geo-effective (Earth
facing) Coronal Mass Ejection (CME) affected
our planet. A weak CME swept
past our planet at 2330 UTC on 02/08/09,
creating a minor ionospheric storm
with a Kp of 4-5. High and mid latitude
visible aurora displays did not
occur.
During the outlook period the
probability of an Earth directed Coronal Mass
Ejection (CME) is placed at
40%.
The Wang-Sheeley Model Interplanetary Magnetic Field (IMF) Polarity
at Earth
prediction is for a continued negative polarity thru 02/08/12, then
shift to
positive from 02/08/13-16. When the polarity of the IMF is negative
a
visible mid latitude Aurora display is likely as a CME strikes the
Earth's
magnetic field.
During the outlook period the probability of a
visible mid latitude Aurora
display is placed at 40%.
As the Kp index
reaches 3-4, the aurora oval begins expanding equatorward in
magnetic
latitude and
generally begins having a negative impact on high latitude
medium frequency
propagation paths. A Kp index of 5 or higher begins to have
a negative
impact on high latitude high frequency shortwave propagation
paths. However
at times skewed path propagation conditions can compensate for
high latitude
propagation path auroral absorption.
During the previous
7 day period our planet did encounter a solar wind
stream flowing from a
geo-effective (Earth facing) coronal hole.
Two Coronal holes are in a
geoeffective position as of 02/08/12. Attendant
solar streams may create
occasional unsettled to active conditions Kp- 3-4
during the
period.
STRATOSPHERIC WARMING-
During the outlook period
increased winter like day and year round night
time D layer absorption of
medium frequency signals tied to stratospheric
warming should not
occur.
Stratospheric warming is a major temperature change of the winter
time polar
and middle atmosphere from the tropopause (where the troposphere
transitions
into the stratosphere) to the base (D-layer) of the ionosphere,
lasting for
many days at a time and characterized by a warming of the
stratospheric
temperature by some tens of degrees (temperature
inversion).
As the stratosphere lies below the ionosphere, which is at
mesosphere and
thermosphere height, you would not expect to see stratospheric
warming
effect medium frequency propagation in any way BUT medium frequency
signals
do refract off of temperature inversions and moisture discontinuities
and a
temperature inversion is involved with stratospheric warming. So
it's
possible that a medium
frequency signal could do any number of things
when refracting off of a
temperature inversion, at any height.
Also
stratospheric warming (STRATWARM) has a negative effect on medium
frequency
propagation, due to increasing medium frequency radio wave
absorption by the
D layer, via upward propagating Internal Gravity Waves
(IGW).
Also I
have observed that stratospheric warming usually coincides with
major
jetstream circulation pattern changes and movement of Arctic air masses
from
Siberian Russia across the pole to Canada and the U.S.
7 DAY
FORECAST OUTLOOK-
Barring any sudden >MeV (10+0) elevated proton
producing solar flares and
later (2-3 day) arriving magnetic disturbances
with Kp indices of 3 or
higher, overall propagation conditions will be near
seasonal normal.
Expect fair to good domestic propagation conditions in
the northern
hemisphere out to approximately 1050 miles.
Expect good
to very good domestic propagation conditions in the southern
hemisphere out
to
approximately 1050 miles.
"High latitude" northern hemispheric (TA)
Trans Atlantic, (TP) Trans Pacific
and cross equatorial propagation
conditions in excess of approximately 3000
miles should be poor to
fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP)
Trans Pacific
and cross equatorial propagation conditions in excess of
approximately 3000
miles should be good.
"Mid latitude" northern
hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
and cross equatorial
propagation conditions in excess of approximately 3000
miles should be fair
to good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP)
Trans Pacific
and cross equatorial propagation conditions in excess of
approximately 3000
miles should be good to very good.
"Low latitude"
northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific
propagation
conditions in excess of approximately 3000 miles should be fair
to
good.
"Low latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans
Pacific
propagation conditions in excess of approximately 3000 miles should
be good.
There will be "moderate to high" lightning induced QRN levels in
mid and low
latitude areas of the northern hemisphere tied to warm season
thunderstorms
and tropical systems during the forecast
period.
Occasional lightning induced QRN will occur across the mid and
low latitude
areas of the southern hemisphere, with an endless series of
winter time
approaching cold fronts and surface extra-tropical low pressure
systems.
High to moderate lightning induced QRN will continue in the
vicinity of the
tropical ITCZ and across equatorial regions.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook Update #2002-18A Updated 11:00 AM EDT 02/08/08
As predicted in our last outlook sunspot region 10057 produced an M1.1 flare at 0126 UTC on 02/08/07. Fortunately though 10057 has now rotated out of view over the western limb of the sun.
In a recent development sunspot region 10061 has developed rapidly and now contains a delta magnetic
structure, which poses a threat for near geo-effective (earth facing) X class solar flares and
associated elevated proton flux events >10 MeV (10+0), coronal mass ejections (CMEÂ’s), ionospheric
storms and visible mid latitude aurora displays.
-----
KN4LF 7 Day Medium Frequency Radio
Propagation Outlook #2002-18 Published 4:00 PM EDT 02/08/04 For
02/08/05-02/08/11.
Though this outlook is aimed primarily at medium
frequencies, it is also applicable to HF frequencies.
Due to the international scope of the amateur/SWL radio community I have adopted the
date format of yy/mm/dd.
REVIEW-
This is my first outlook issued
since mid May 2002 and I thought that a brief review of space weather conditions
between mid May and the end of July would be useful. The initial period which
coincided with the summer/winter equinox was relatively quiet and uneventful, a
common occurrence. However by July activity increased sharply. In a sense the
month of July actually appeared to represent a third peak in our present sunspot
cycle maximum, not something low band DX'ers want to see happen.
During
the period 02/05/15 and 02/07/31 the daily solar flux value ranged between 129
and 275. During the month of July 2002 29 M class solar flares occurred, with 5
X class solar flares and 1 so far in this month of August. In contrast January
through June 2002 saw only 2 X class solar flares.
Recent daily sunspot
numbers have ranged between a low of 85 on 02/07/02, peaking at 323 on 02/08/03,
the highest number since March 2001.
Also the month of July saw 5 >10
MeV (10+0) elevated energetic proton events following a very quiet
period.
The previous 7 day period was active concerning space weather and
geomagnetic activity.
As we continue to move deeper into the southern
hemisphere winter and northern hemisphere summer solstices, aurora activity is
likely to increase.
ENERGETIC PROTON FLUX-
During the previous
seven day period no >10 MeV (10+0) proton events occurred.
During the
outlook period the probability of an elevated proton flux event >10 MeV
(10+0) is placed at 40%.
An elevated proton flux level >10 MeV (10+0)
creates increased winter time day and year round night time D layer absorption
of medium wave frequencies, especially on high latitude propagation paths but it
can also negatively impact mid latitudes, depending on the intensity of the
event. Elevated energetic proton events too small to be categorized as a Polar
Cap Absorption event (PCA) can still impact high and mid level medium frequency
propagation paths in the form of excessive D layer absorption. This fact is
still stubbornly opposed by some otherwise very knowledgeable space weather
physicists over dependent on threshold Riometer readings.
((((Note, high
latitude medium frequency radio propagation paths can still be disturbed for
days and up to weeks, following the end of an official >10 MeV (10+0) proton
event.))))
SOLAR FLUX-
During the previous 7 day period the
daily solar flux values ranged between 227 and 156.
During the outlook
period the daily solar flux values should range between approximately 190 and
145.
During the previous 7 day period the background X-ray flux levels
ranged between C1.2 and C1.9.
Background x-ray flux levels can impact
medium frequency signals in a negative manner. Background x-ray flux levels of
C1 or greater creates increased D layer absorption of 160 meter signals and B9
or greater creates increased D layer absorption of AM broadcast band
signals.
Unfortunately there will be no important F2 layer propagation
openings on 6 meters during the outlook period due to relatively low daily solar
flux values and normal summer season depression of F2 ionization levels in the
northern hemisphere.
However occasional Auroral propagation is possible,
with Sporadic E (Es) and Trans Equatorial Scatter (TEQ) openings are
increasingly probable.
High solar flux values are generally considered to
be detrimental to propagation of medium frequency signals both domestic and
Trans Atlantic (TA) & Trans Pacific (TP), as more absorption can be present
via the transmitted signals' two trips through the D layer at the takeoff and
arrival points.
Most "strong" longer haul medium frequency DX signals in
excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop
propagation modes. Therefore high solar flux values can aid in long haul medium
frequency propagation paths in excess of 3000 miles, as a high solar flux value
ensures a strong F layer part of the E Valley-F layer duct or Chordal Hop
propagation mechanism.
However high solar activity in the form of
increased ionization created by Ultraviolet and X-Ray radiation can fill in the
E Valley region and interfere with the E Valley-F layer ducting mechanism. In a
sense the E Valley-F layer duct is closed on one or both ends of a propagation
path and the transmitted MF RF signal only propagates between the E layer and
land/ocean surface, with a higher angle and more loss.
SUNSPOT
REGIONS/SOLAR FLARES
During the previous 7 day period the visible sunspot
groups were active, with four M class solar flares and one X class solar flare.
Fortunately any/all attendant Coronal Mass Ejections (CME's) were non
geo-effective (earth facing).
Sunspot group number 10039 at S16W83, 10044
at S08W59, 10050 at S08W73 and 10057 at S08W25 contain beta-gamma magnetic
configurations that harbor energy for medium to large and powerful Earth facing
M class solar flares. However 10039 has slipped around the west limb of the sun
and 10050 and 10044 will follow shortly. This will reduce the chance of M class
solar flares during the next several days but as mentioned 10057 is in a
geo-effective position (earth facing) to hurl a Coronal Mass Ejection (CME)
should it erupt. 10057 also holds potential in future days to grow a
beta-gamma-delta magnetic structure that would harbor energy for huge and
powerful Earth facing X class solar flares.
During the outlook period I
place the chance of a C class solar flare at 100%, an M class at 75%, dropping
to 50% by day 3 and an X class at 10%.
An earthward facing C4 or higher
class solar flare can elevate the proton flux above 10 MeV (10+0) and initiate
large scale high and mid latitude propagation path absorption on the AM
broadcast band and 160 meters, both stateside and DX, as a transfer of increased
density and RF signal absorption from the day side D layer to night side of the
ionosphere occurs through high level neutral winds. Unfortunately even smaller
C3 solar flares can create hour to hour and night to night variations in signal
strength on medium frequencies.
High and mid latitude Trans Atlantic (TA)
and Trans Pacific (TP) propagation paths tend to open up after a significant
period of time passes without an elevated energetic proton event of >10 MeV
(10+0). This fact is still stubbornly opposed by some otherwise very
knowledgeable space weather physicists over dependent on threshold Riometer
readings.
Openings also occur when the solar background x-ray level falls
back to or below C1 for 160 meters and B9 for the AM broadcast
band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE
AURORA-
During the previous 7 day period at least one minor geo-effective
(Earth facing) Coronal Mass Ejection (CME) affected our planet. A weak CME swept
past our planet at 2311 UTC on 02/08/01, creating a minor ionospheric storm with
a Kp of 5. High and mid latitude visible aurora displays did
occur.
During the outlook period the probability of an Earth directed
Coronal Mass Ejection (CME) is placed at 40%.
The Wang-Sheeley Model
Interplanetary Magnetic Field (IMF) Polarity at Earth prediction is for
continued a continued negative polarity thru 02/08/08. When the polarity of the
IMF is negative a visible mid latitude Aurora display is likely as a CME strikes
the Earth's magnetic field.
During the outlook period the probability of
a visible mid latitude Aurora display is placed at 40%.
As the Kp index
reaches 3-4, the aurora oval begins expanding equatorward in magnetic latitude
and generally begins having a negative impact on high latitude medium frequency
propagation paths. A Kp index of 5 or higher begins to have a negative impact on
high latitude high frequency shortwave propagation paths. However at times
skewed path propagation conditions can compensate for high latitude propagation
path auroral absorption.
During the previous 7 day period our planet did
not encounter a solar wind stream flowing from a geo-effective (Earth facing)
coronal hole.
Two Coronal holes are in a geoeffective position as of
02/08/02. Attendant solar streams may create occasional unsettled to active
conditions Kp- 3-4 during the period.
STRATOSPHERIC
WARMING-
During the outlook period increased winter like day and year
round night time D layer absorption of medium frequency signals tied to
stratospheric warming should not occur.
Stratospheric warming is a major
temperature change of the winter time polar and middle atmosphere from the
tropopause (where the troposphere transitions into the stratosphere) to the base
(D layer) of the ionosphere, lasting for many days at a time and characterized
by a warming of the stratospheric temperature by some tens of degrees
(temperature inversion).
As the stratosphere lies below the ionosphere,
which is at mesosphere and thermosphere height, you would not expect to see
stratospheric warming effect medium frequency propagation in any way BUT medium
frequency signals do refract off of temperature inversions and moisture
discontinuities and a temperature inversion is involved with stratospheric
warming. So it's possible that a medium frequency signal could do any number of
things when refracting off of a temperature inversion, at any
height.
 Also stratospheric warming (STRATWARM) has a negative effect on
medium frequency propagation, due to increasing medium frequency radio wave
absorption by the D layer, via upward propagating Internal Gravity Waves
(IGW).
Also I have observed that stratospheric warming usually coincides
with major jetstream circulation pattern changes and movement of Arctic air
masses from Siberian Russia across the pole to Canada and the U.S.
7
DAY FORECAST OUTLOOK-
Barring any sudden >10 MeV (10+0) elevated
proton producing solar flares and later (2-3 day) arriving magnetic disturbances
with Kp indices of 3 or higher, overall propagation conditions will be near
seasonal normals.
Expect fair to good domestic propagation
conditions in the northern hemisphere out to approximately 1500
miles.
Expect good to very good domestic propagation conditions in the
southern hemisphere out to approximately 1500 miles.
"High latitude"
northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific and cross
equatorial propagation conditions in excess of approximately 3000 miles should
be poor to fair.
"High latitude" southern hemispheric (TA) Trans
Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in
excess of approximately 3000 miles should be good.
"Mid latitude"
northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial
propagation conditions in excess of approximately 3000 miles should be fair to
good.
"Mid latitude" southern hemisphere (TA) Trans Atlantic, (TP) Trans
Pacific and cross equatorial propagation conditions in excess of approximately
3000 miles should be good to very good.
"Low latitude" northern
hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in
excess of approximately 3000 miles should be fair to good.
"Low latitude"
southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific propagation
conditions in excess of approximately 3000 miles should be very
good.
There will be "moderate to high" lightning induced QRN
levels in mid and low latitude areas of the northern hemisphere tied to warm
season thunderstorms and tropical systems during the forecast
period.
Occasional lightning induced QRN will occur across the mid and
low latitude areas of the southern hemisphere, with an endless series of winter
time approaching cold fronts and surface extra-tropical low pressure
systems.
High to moderate lightning induced QRN will continue in the
vicinity of the tropical ITCZ and across equatorial regions.
Back To The Top
KN4LF 7 Day Medium Frequency Radio Propagation Outlook #2002-17 Published 4:00 PM EST 02/05/13 For 02/05/13-02/05/19.
Sorry for the delay in distributing the outlook, as yesterday was spent observing Mothers Day.
Though this outlook is aimed primarily at medium frequencies, it is also applicable to HF frequencies.
Due to the international scope of the amateur/SWL radio community I have adopted the date format of yy/mm/dd.
The previous 7 day period was relatively quiet, with only two medium sized solar flare events, no >10 MeV (10+0) elevated proton events, one weak and one strong Earth directed coronal mass ejection and one ionospheric storm. As we continue to move closer to the southern hemisphere winter and northern hemisphere summer solstices, itÂ’s common to have less space weather activity.
PROTON FLUX-
During the previous 7 day period no >10 MeV (10+0) proton events occurred.
During the outlook period the probability of an elevated proton flux event >10 MeV (10+0) is placed at 40%.
An elevated proton flux level >10 MeV (10+0) creates increased winter day and year round night time D layer absorption of medium wave frequencies, especially on high latitude propagation paths but can also negatively impact mid latitudes, depending on the intensity of the event. Elevated proton events too small to be categorized as a polar cap absorption event (PCA) can still impact medium frequency propagation in a negative fashion. This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists over dependent on threshold Riometer readings.
((((Note, high latitude medium frequency radio propagation paths can still be disturbed for days and up to weeks, following the end of an official (>10 MeV) proton event.))))
SOLAR FLUX-
During the previous 7 day period the daily solar flux values ranged between 193 and 180.
During the outlook period the daily solar flux values should range between approximately 200 and 170.
Unfortunately there will be no important F2 layer propagation openings on 6 meters during the outlook period due to relatively low daily solar flux values and normal summer season depression of F2 ionization levels in the northern hemisphere.
However Sporadic E (Es) and (TEQ) openings are increasingly probable.
High solar flux values are generally considered to be detrimental to propagation of medium frequency signals both domestic and Trans Atlantic (TA) & Trans Pacific (TP), as more absorption can be present via the transmitted signalsÂ’ two trips through the D layer at the takeoff and arrival points.
Most strong long haul medium frequency DX signals in excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high solar flux values can aid in long haul medium frequency propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong F layer part of the E Valley-F layer duct mechanism.
However high solar activity in the form of increased ionization created by Ultraviolet and X-Ray radiation can fill in the E Valley region and interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F layer duct is closed on one or both ends of a propagation path and the transmitted MF RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS/SOLAR FLARES
After a very active 28 day period with numerous sunspot groups, activity continues to slowly settle down as we move towards the solstices.
Sunspot region #Â’s 9934 at S16W72 and 9937 at S08W50 contain twisted delta-class magnetic fields that harbor energy for huge and powerful Earth facing X-class solar flares. However weakening is now occurring and is expected to continue during the next several days, as the groups rotate around the west limb of the sun.
During the previous 7 day period the largest observed solar flare was an M1.4 which erupted at 1129 UTC on 02/05/11.
An M1.3 class solar flare also erupted at 0339 UTC on 02/05/07.
During the previous 7 day period the background X-ray flux levels ranged between C2.6 and B6.2.
During the outlook period I place the chance of a C class solar flare at 100%, an M class at 50% and an X class at 10%.
An earthward facing C4 or higher class solar flare can elevate the proton flux above 10 MeV (10+0) and initiate large scale high and mid latitude propagation path absorption on the AM broadcast band and 160 meters, both stateside and DX, as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds. Unfortunately even smaller C3 solar flares can create hour to hour and night to night variations in signal strength on medium frequencies.
High and mid latitude Trans Atlantic (TA) and Trans Pacific (TP) propagation paths tend to open up after a significant period of time passes without an elevated energetic proton event of >10 MeV (10+0). This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists over dependent on threshold Riometer readings.
Openings also occur when the solar background x-ray level falls back to or below C1 for 160 meters and B9 for the AM broadcast band.
CORONAL MASS EJECTIONS/IONOSPHERIC STORMS/VISIBLE AURORA-
During the previous 7 day period two Earth facing Coronal Mass Ejections (CME) affected our planet. The first weaker CME swept past our planet at 0900 UTC on 02/05/09, creating a moderate period with unsettled conditions Kp- 3. No significant visible aurora displays were observed. The second stronger CME swept past our planet at 1000 UTC on 02/05/11, creating an 18 hour period of active Kp-4 to major storm Kp-6 and visible display of Aurora.
During the previous 7 day period our planet did not encounter a solar wind stream flowing from an Earth facing coronal.
No large coronal holes are expected to arrive in an Earth facing position during the outlook period. However small short lived Earth facing coronal holes may create occasional unsettled to active conditions Kp- 3-4.
During the outlook period the probability of an Earth directed Coronal Mass Ejection (CME) is placed at 40%.
As the Kp index reaches 3-4, the aurora oval regions begin expanding equatorward in magnetic latitude and generally begin having a negative impact on high latitude medium frequency propagation paths. A Kp index of 5 or higher begins to have a negative impact on high latitude high frequency shortwave propagation paths. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period increased winter like day and year round night time D layer absorption of medium frequency signals tied to stratospheric warming should not occur.
Stratospheric warming is a major temperature change of the winter time polar and middle atmosphere from the tropopause (where the troposphere transitions into the stratosphere) to the base (D layer) of the ionosphere, lasting for many days at a time and characterized by a warming of the stratospheric temperature by some tens of degrees (temperature inversion).
As the stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you would not expect to see stratospheric warming effect medium frequency propagation in any way BUT medium frequency signals do refract off of temperature inversions and moisture discontinuities and a temperature inversion is involved with stratospheric warming. So it's possible that a medium frequency signal could do any number of things when refracting off of a temperature inversion, at any height.
Also stratospheric warming (STRATWARM) has a negative effect on medium frequency propagation, due to increasing medium frequency radio wave absorption by the D layer, via upward propagating Internal Gravity Waves (IGW).
Also I have observed that stratospheric warming usually coincides with major jetstream circulation pattern changes and movement of Arctic air masses from Siberian Russia across the pole to Canada and the U.S.
7 DAY FORECAST OUTLOOK-
Barring any sudden >10 MeV (10+0) elevated proton producing solar flares and later (2-3 day) arriving magnetic disturbances with Kp indices of 3 or higher, overall propagation conditions will be near normal.
Expect good domestic propagation conditions in both hemispheres out to approximately 1500 miles.
Expect fair domestic propagation conditions out to approximately 3000 miles in the northern hemisphere and good propagation conditions out to approximately 3000 miles in the southern hemisphere.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in excess of approximately 3000 miles should be fair to good.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in excess of approximately 3000 miles should be good to very good.
”Mid latitude” northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be good.
”Mid latitude” southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be good to very good.
There will be "moderate to high" lightning induced QRN levels in south central and south eastern North America during the forecast period.
Occasional lightning induced QRN will also occur across the northern hemisphere, with an endless series of spring time approaching cold fronts and surface extra-tropical low pressure systems.
High to moderate tropical related lightning induced QRN will continue across equatorial regions.
Continuous high summer time related lightning induced QRN will continue to wane across the southern hemisphere, however occasional lightning induced QRN will be on the increase with an endless series of fall approaching cold fronts and surface extra-tropical low pressure systems.
Back To The Top
KN4LF 7 Day Medium Wave Radio Propagation Outlook #2002-16 Published 4:00 PM EST 02/05/05 For 02/05/06-02/05/12.
Though this outlook is aimed primarily at medium frequencies, it is also applicable to HF frequencies.
Due to requests from our fellow radio brethren in the international radio community I have adopted the date format of yy/mm/dd.
The past 7 day outlook period was quiet, with only one medium sized solar flare, one brief >10 MeV (10+0) elevated proton event, one non earth directed coronal mass ejection and no ionospheric storms. As we move closer to the southern hemisphere winter and northern hemisphere summer solstices, itÂ’s not uncommon to have less space weather activity.
PROTON FLUX-
A very brief >10 MeV (10+1) proton event began at approximately 0000 UTC on 02/05/02 and ended at approximately 1200 UTC on 02/05/02. The source was an unidentified non earth facing solar flare.
During the outlook period the probability of an elevated proton flux event >10 MeV (10+0) is placed at 30%.
A proton flux level >10 MeV (10+0) creates increased day AND night time D layer absorption on medium wave frequencies, especially on high latitude propagation paths but can also negatively impact mid latitudes, depending on the intensity of the event. Elevated proton events to small to categorized as a polar cap absorption event (PCA) can still impact medium frequency propagation in a negative fashion. This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists.
((((NOTE!!! High latitude medium frequency radio propagation paths may still be disturbed for days and up to weeks, following the end of an official proton event.))))
SOLAR FLUX-
During the past 30 day outlook period the daily solar flux levels ranged between 226 and 147. The 147 was the lowest daily solar flux observed since 01/08/15. During the past 7 day outlook period the daily solar flux levels ranged between 192 and 147.
During the outlook period the daily solar flux should range between approximately 210 and 180.
Unfortunately there will be no important F2 layer propagation openings on 6 meters during the outlook period due to low daily solar flux values and normal summer season depression of F2 ionization levels in the northern hemisphere. However Sporadic E (Es) and (TEQ) openings are possible.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signalsÂ’ two trips through the D layer.
Most long haul medium wave DX signals in excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increase ionization created by ultraviolet and x-ray radiation can fill in the E Valley region and interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS/SOLAR FLARES/CORONAL MASS EJECTIONS-
After a very active 21 day period with numerous sunspot groups, activity continues to slowly wane.
Sunspot region #9934 at S17E35, which spans an area equal to the surface of almost three planet Earths, developed a twisted delta-class magnetic field a couple of days ago and itÂ’s fields harbor energy for powerful X-class solar flares. However weakening is expected during the next several days.
Solar region #9937 at S17E15 is developing slowly and is capable of minor M class flares.
Solar region #9929 at N21W41 has shown the most change, increasing in area, extent and spot count.
The largest observed solar flare in the previous 7 day outlook period was an M1.1, which erupted at 0819 UTC on 02/04/30.
Numerous smaller C class solar flares also occurred.
During the past 7 day outlook period the background X-ray flux levels ranged from C1.1 to B6.
During the past seven day outlook period one non earth facing coronal mass ejection (CME) affected our planet in the form of a brief and slightly elevated > 10 MeV (10+0) proton level.
During the outlook period I place the chance of a C class solar flare at 100%, an M class at 50% and an X class at 20%.
An earthward facing C9 or higher class solar flare can elevate the proton flux above 10 MeV (10+0) and initiate large scale high and mid latitude propagation path absorption on the AM broadcast band and 160 meters, both stateside and DX, as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds. Unfortunately even smaller C3 solar flares can create hour to hour and night to night variations in signal strength on medium frequencies. High and mid latitude TA and TP propagation paths tend to open up when the solar background x-ray level falls back to or below C1 on 160 meters and B9 on the AM broadcast band. This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists. Background X-ray radiation in the 1 to 10 Angstrom range (hard X- rays) is the source of medium frequency D layer ionization.
IONOSPHERIC STORMS-
The earth entered a solar wind stream flowing from a small geo-effective coronal hole on 02/05/01, creating disturbed conditions in the earthÂ’s magnetosphere, with an elevated Kp index of 3.
During the outlook period no coronal mass ejection (CME) related ionospheric storms are expected.
No large coronal holes will arrive in a geoeffective (earth facing) position during the outlook period. However occasional small earth facing coronal holes may create occasional disturbed conditions with a an elevated Kp index of 3-4.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation. A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period elevated day and night time D layer medium frequency signal absorption tied to continued stratospheric warming should not occur.
Stratospheric warming is a major temperature change of the winter time polar and middle atmosphere from the tropopause (where the troposphere transitions into the stratosphere) to the base (D layer) of the ionosphere, lasting for many days at a time and characterized by a warming of the stratospheric temperature by some tens of degrees.
As the Stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you would not expect to see stratospheric warming effect mediumwave frequency propagation in any way BUT mediumwave frequency signals do refract off of temperature inversions and moisture discontinuities and a temperature inversion is involved with stratospheric warming. So it's possible that a mediumwave frequency signal could do any number of things when refracting off of a temperature inversion, at any height. Also stratospheric warming (STRATWARM) has an effect on the D layer by increasing radio wave absorption.
Also I've observed many times that stratospheric warming can coincide with major jetstream circulation pattern changes and movement of Arctic air from Siberian Russia across the pole to Canada and the U.S.
OUTLOOK-
Overall propagation conditions will be near normal.
Expect good domestic propagation conditions in both hemispheres out to approximately 1500 miles.
Expect fair domestic propagation conditions out to approximately 3000 miles in the northern hemisphere and good propagation conditions out to approximately 3000 miles in the southern hemisphere.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in excess of approximately 3000 miles should be fair to good.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in excess of approximately 3000 miles should be good to very good.
”Mid latitude” northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be good.
”Mid latitude” southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be good to very good.
There will be "moderate to high" lightning induced QRN levels in south central and south eastern North America during the forecast period.
Occasional lightning induced QRN will also occur across the northern hemisphere, with an endless series of spring time approaching cold fronts and surface extra-tropical low pressure systems.
High to moderate tropical related lightning induced QRN will continue across equatorial regions.
Continuous high summer time related lightning induced QRN will continue to wane across the southern hemisphere, however occasional lightning induced QRN will be on the increase with an endless series of fall approaching cold fronts and surface extra-tropical low pressure systems.
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KN4LF 7 Day Medium Wave Radio Propagation Outlook #2002-15 Published 4:00 PM EST 02/04/28 For 02/04/29-02/05/05.
Though this outlook is aimed primarily at medium frequencies, it is also applicable to HF frequencies.
Due to requests from our fellow radio brethren in the international radio community I have adopted the date format of yy/mm/dd.
After a very active space weather period that we have had during the past 14 day outlook period, with numerous significant solar flares, elevated proton level events, coronal mass ejections and ionospheric storms, space weather occurrences were mainly nonexistent.
ItÂ’s not uncommon to have more space weather activity around the fall and spring equinoxes and less activity around the winter and summer solstices.
PROTON FLUX-
A greater then 10 MeV (10+3) proton event that began at approximately 0225 UTC on 02/04/21 finally ended at approximately 1500 UTC on 02/04/28. This elevated proton flux event reached a maximum of 2520 pfu (10+3) at approximately 0000 UTC on 02/04/21. The source was an enormous X1.5 solar flare ejected from sunspot group # 9906.
During the outlook period the probability of an elevated proton flux event greater then 10 MeV (10+0) is placed at 20%.
A proton flux level >10 MeV (10+0) creates increased day AND night time D layer absorption on medium wave frequencies, especially on high latitude propagation paths but can also negatively impact mid latitudes, depending on the intensity of the event. Elevated proton events to small to categorized as a polar cap absorption event (PCA) can still impact medium frequency propagation in a negative fashion. This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists.
((((NOTE!!! High latitude radio propagation paths may still be disturbed for days and up to weeks, following the end of an official proton event.))))
SOLAR FLUX-
During the past 7 day outlook period the daily solar flux levels ranged between 179 and 157.
During the outlook period the daily solar flux should range between approximately 200 and 155.
Unfortunately there will be no important F2 layer propagation openings on 6 meters during the outlook period due to low daily solar flux values and normal summer season depression of F2 ionization levels in the northern hemisphere. However Sporadic E (Es) and (TEQ) openings are possible.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signalsÂ’ two trips through the D layer.
Most long haul medium wave DX signals in excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increase ionization created by ultraviolet and x-ray radiation can fill in the E Valley region and interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS/SOLAR FLARES/CORONAL MASS EJECTIONS-
After a very active 14 day period with numerous sunspot groups, activity continues to wane.
I can’t remember the last time I said this but no sunspot region #’s currently contain a “beta gamma” magnetic field structure that would pose a threat for large earth directed M class solar flares, coronal mass ejections (CME’s) and elevated proton events. There is a small chance that solar region #9915 will produce an isolated small M class flare.
The largest observed solar flare in the previous seven day outlook period was an M1.3, which erupted from solar region #9906 at 2154 UTC on 02/04/24.
During the past seven day outlook period one coronal mass ejection (CME) affected our planet, beginning at 0450 UTC on 02/04/23, tied to the massive X1.5 solar flare from sunspot group #9906.
During the outlook period I place the chance of a C class solar flare at 100%, an M class at 30% and an X class at 10%.
An earthward facing C9 or higher class solar flare can elevate the proton flux above 10 MeV (10+0) and initiate large scale high and mid latitude propagation path absorption on the AM broadcast band and 160 meters, both stateside and DX, as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds. Unfortunately even smaller C3 solar flares can create hour to hour and night to night variations in signal strength on medium frequencies.
IONOSPHERIC STORMS-
During the past seven day outlook period, tied to the above mentioned coronal mass ejection (CME), a short duration ionospheric storm occurred, with elevated Kp indices of 5-6.
During the outlook period no (CME) related ionospheric storms are expected.
The earth entered a solar wind stream flowing from a small geo-effective coronal hole on 02/04/27, creating disturbed conditions in the earthÂ’s magnetosphere,
with an elevated Kp index of 3.
Another larger coronal hole will arrive in a geoeffective position on 02/04/28-29, creating continued disturbed conditions with a Kp index of 3-4 expected.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation. A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period elevated day and night time D layer medium frequency signal absorption tied to continued stratospheric warming should not occur.
Stratospheric warming is a major temperature change of the winter time polar and middle atmosphere from the tropopause (where the troposphere transitions into the stratosphere) to the base (D layer) of the ionosphere, lasting for many days at a time and characterized by a warming of the stratospheric temperature by some tens of degrees.
As the Stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you would not expect to see stratospheric warming effect mediumwave frequency propagation in any way BUT mediumwave frequency signals do refract off of temperature inversions and moisture discontinuities and a temperature inversion is involved with stratospheric warming. So it's possible that a mediumwave frequency signal could do any number of things when refracting off of a temperature inversion, at any height. Also stratospheric warming (STRATWARM) has an effect on the D layer by increasing radio wave absorption.
Also I've observed many times that stratospheric warming can coincide with major jetstream circulation pattern changes and movement of Arctic air from Siberian Russia across the pole to Canada and the U.S.
OUTLOOK-
Overall propagation conditions will be greatly improved to near normal compared to the previous 14 days, now that the prolonged elevated proton flux event of greater then 10 MeV (10 +3) has ended.
Expect good domestic propagation conditions in both hemispheres out to approximately 1500 miles.
Expect fair domestic propagation conditions out to approximately 3000 miles in the northern hemisphere and good propagation conditions out to approximately 3000 miles in the southern hemisphere.
"High latitude" northern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in excess of approximately 3000 miles should be fair.
"High latitude" southern hemispheric (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in excess of approximately 3000 miles should be good.
”Mid latitude” northern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be good.
”Mid latitude” southern hemisphere (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be good to very good.
There will be "high" lightning induced QRN levels in south central and south eastern North America during the forecast period.
Occasional lightning induced QRN will also occur across the northern hemisphere, with an endless series of spring time approaching cold fronts and surface extra-tropical low pressure systems.
High to moderate tropical related lightning induced QRN will continue across equatorial regions.
Continuous high summer time related lightning induced QRN will continue to wane across the southern hemisphere, however occasional lightning induced QRN will be on the increase with an endless series of fall approaching cold fronts and surface extra-tropical low pressure systems.
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KN4LF 7 Day Medium Wave Radio Propagation Outlook #2002-14 Published 1:00 PM EST 02/04/21 For 02/04/22-02/04/28.
Though this outlook is aimed primarily at medium frequencies, it is also applicable to HF frequencies.
Due to requests from our fellow radio brethren in the international radio community I have adopted the date format of yy/mm/dd.
Wow what an active space weather period we have had during the past seven day outlook period, with numerous significant solar flares, elevated proton level events, coronal mass ejections and ionospheric storms!
PROTON FLUX-
A greater then 10 MeV (10+0) proton event began at approximately 0854 UTC on 02/04/17 and ended at approximately 0200 UTC on 02/04/20. This elevated proton flux event reached a maximum of 24 pfu (10+1) and the source was an M2.7 solar flare ejected from sunspot group # 9906.
A new greater then 10 MeV (10+0) proton event began at approximately 0054 UTC 02/04/21. This elevated proton flux event has reached a maximum of 1837 pfu (10+3) so far and the source is an X1.5 solar flare ejected from sunspot group #9906.
During the outlook period the probability of an elevated proton flux event greater then 10 MeV (10+0) is placed at 100% during the next 48 hours and then at 50% during the remainder of the outlook period.
A proton flux level >10 MeV (10+0) creates increased day and night time D layer absorption on medium wave frequencies, especially on high latitude propagation paths but can also negatively impact mid latitudes, depending on the intensity of the event. Elevated proton events to small to categorized as a polar cap absorption event (PCA) can still impact medium frequency propagation in a negative fashion.
((((NOTE!!! High latitude radio propagation paths may still be disturbed for days and up to weeks, following the end of an official proton event.))))
SOLAR FLUX-
During the past 7 day outlook period the daily solar flux levels ranged
between 215 and 175.
During the outlook period the daily solar flux should range between approximately 225 and 174.
Unfortunately there will be no important F2 layer propagation openings on 6 meters during the next 7 days due to low daily solar flux values and normal summer season depression of F2 ionization in the northern hemisphere. However Sporadic E (Es) and (TEQ) openings are possible.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signalsÂ’ two trips through the D layer.
Most long haul medium wave DX signals in excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increase ionization created by ultraviolet and x-ray radiation can fill in the E Valley region and interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS/SOLAR FLARES/CORONAL MASS EJECTIONS-
After a very active 7 day period with numerous sunspot groups, things are starting to calm down again.
Solar region # 9906 at S14W79 continues to contain a “beta gamma delta” magnetic field structure that poses a threat for more massive earth directed X class solar flares, coronal mass ejections (CME’s) and elevated proton events. Fortunately #9906 will be rotating around the western limb of the sun soon.
Solar region # 9912 at N10E02 contains a “beta gamma” magnetic structure and poses a threat for large earth directed M class solar flares, coronal mass ejections, elevated proton events and may develop a “beta gamma delta” magnetic field structure also in coming days.
The largest observed solar flare in the previous seven day outlook period was an X1.5 which erupted from solar region #9906 on 02/04/21 at 0054 UTC, creating an R2 shortwave fadeout(SWF), that effected Australia, SE Asia, China, Siberia, Hawaii and Micronesia.
Smaller but still significant M3.7, M2.7, M2.6, M1.3, C9.4 and C9.3 solar flares also occurred.
During the past seven day outlook period two coronal mass ejections (CMEÂ’s) affected our planet, one on 02/04/17 and the other on 02/04/19, both tied to sunspot group #9906. A third coronal mass ejection tied to sunspot group #9906 will graze the earth on 02/04/22-23.
During the next 48 hour outlook period I place the chance of a C class solar flare at 100%, an M class at 75% and an X class at 30%. Thereafter I place the chance of a C class solar flare at 100%, an M class at 60% and an X class at 10%.
An earthward facing C9 or higher class solar flare can elevate the proton flux above 10 MeV (10+0) and initiate large scale high and mid latitude propagation path absorption on the AM broadcast band and 160 meters, both stateside and DX, as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds. Unfortunately even smaller C3 solar flares can create hour to hour and night to night variations in signal strength on medium frequencies.
IONOSPHERIC STORMS-
During the past seven day outlook period two signicant coronal mass ejections (CMEÂ’s) effected our planet, one on 02/04/17 and another on 02/04/19, both tied to sunspot group #9906. A third coronal mass ejection tied to sunspot group #9906 will graze the earth on 02/04/22-23.
Two distinctly seperate ionospheric storms occurred during the past seven day outlook period, tied to the above mentioned coronal mass ejections (CMEÂ’s). Elevated Kp indices of 5-7 and observed aurora displays did occur.
During the next two days of the new outlook period Kp indices should drop back below a 4, followed by renewed elevated Kp indices of 5-6, in association with the next coronal mass ejection, tied to todayÂ’s X1.5 class solar flare, that should will graze the earth on 02/04/22-23.
A new and substantial coronal hole is emerging near the Sun's east limb. It should be in a geoeffective position in the latter part of the new outlook period, initiating renewed elevated Kp indices of 3-4.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation. A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period elevated day and night time D layer medium frequency signal absorption tied to continued stratospheric warming should not occur.
Stratospheric warming is a major temperature change of the winter time polar and middle atmosphere from the tropopause (where the troposphere transitions into the stratosphere) to the base (D layer) of the ionosphere, lasting for many days at a time and characterized by a warming of the stratospheric temperature by some tens of degrees.
As the Stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you would not expect to see stratospheric warming effect mediumwave frequency propagation in any way BUT mediumwave frequency signals do refract off of temperature inversions and moisture discontinuities and a temperature inversion is involved with stratospheric warming. So it's possible that a mediumwave frequency signal could do any number of things when refracting off of a temperature inversion, at any height. Also stratospheric warming (STRATWARM) has an effect on the D layer by increasing radio wave absorption.
Also I've observed many times that stratospheric warming can coincide with major jetstream circulation pattern changes and movement of Arctic air from Siberian Russia across the pole to Canada and the U.S.
OUTLOOK-
Overall propagation conditions will be
down 6-12 db from normal, due to the recent and present elevated proton flux events of (10 +1-3) .
Note! Increased power and good transmit and receive antennas will be helpful in overcoming the expected poor conditions.
Expect good domestic propagation conditions in both hemispheres out to approximately 1500 miles and fair domestic propagation conditions out to approximately 3000 miles.
"High latitude" northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific propagation conditions in excess of approximately 3000 miles should be poor and cross equatorial propagation conditions in excess of approximately 3000 miles fair to good.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be fair to good.
There will be "high" lightning induced QRN levels in south central and south eastern North America during the forecast period.
Occasional lightning induced QRN will also occur across the northern hemisphere, with an endless series of spring time approaching cold fronts and surface extra-tropical low pressure systems.
High to moderate tropical related lightning induced QRN will continue across equatorial regions.
Continuous high summer time related lightning induced QRN will continue to wane across the southern hemisphere, however occasional lightning induced QRN will be on the increase with an endless series of fall approaching cold fronts and surface extra-tropical low pressure systems.
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KN4LF 7 Day Medium Wave Radio Propagation Outlook Update #2002-13A Published 11:00 PM EST 02/04/20
A very large X1.5 solar flare occurred at 0150 UTC 02/04/21. Within minutes the proton flux level has jumped from 10+0 to 10+2 and is rising. What does this mean? Lot's of D layer absorption of medium frequencies. Sunspot group #9906 is probably the culprit behind this solar flare. If it has released a coronal mass ejection (CME), It will probably be earth facing and renewed F layer damaging elevated Kp indices as high as 7 (ionospheric storm) and associated aurora displays will occur within 1-3 days.
To add insult to injury an extended period with elevated proton flux levels (10+1) and Kp (7) indices due to an earlier solar flare just ended.
-----
KN4LF 7 Day Medium Wave Radio Propagation Outlook #2002-13 Published 6:00 PM EST 02/04/14 For 02/04/15-02/04/21.
(((NOTE!))) Though this outlook is aimed primarily at medium frequencies, it is also very applicable to HF frequencies.
Note! Due to requests from our fellow radio brethren in the international radio community I have adopted the date format of yy/mm/dd.
PROTON FLUX-
A greater then 10 MeV (10+1) proton event began on 02/04/11 at 1800 UTC and lasted approximately 12 hours.
During the outlook period the probability of an elevated proton flux event >10 MeV (10+1) is placed at 50%.
A proton flux level >10 MeV (10+1) creates increased day and night time D layer absorption on medium wave frequencies, especially on high latitude propagation paths but can also negatively impact mid latitudes, depending on the intensity of the event. Elevated proton events to small to categorized as a polar cap absorption event (PCA) can still impact medium frequency propagation in a negative fashion.
((((NOTE!!! High latitude radio propagation paths may still be disturbed for days and up to weeks, following the end of an official proton event.))))
SOLAR FLUX-
During the past 7 day outlook period the daily solar flux levels ranged between 226 and 194.
During the outlook period the daily solar flux should range between approximately 230 and 190.
Unfortunately there will be no important F2 layer propagation openings on 6 meters during the next 7 days, however Sporadic E (Es) and (TEQ) openings are possible.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signalsÂ’ two trips through the D layer.
Most long haul medium wave DX signals in excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increase ionization created by ultraviolet and x-ray radiation can fill in the E Valley region and interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS/SOLAR FLARES/CORONAL MASS EJECTIONS-
Solar region #’s 9893 at N18W53 and #9906 at S15E13 are very large, fast growing and now contain “beta gamma delta” magnetic field structures that pose a threat for massive earth directed X class solar flares, coronal mass ejections (CME’s) and elevated proton events.
Solar region #’s 9900 and 9907 contain a “beta gamma” magnetic structure and poses a threat for large earth directed M class solar flares, coronal mass ejections, elevated proton events and may develop a “beta gamma delta” magnetic field structure also in coming days.
The largest observed solar flare in the previous seven day outlook period was an M8.2 which erupted from solar region #9893 on 02/04/10 at 1231 UTC, creating an R1 shortwave fadeout (SWF).
Smaller M4, M1.4, M1.0, C10, C9.7 and C9.6 solar flares also occurred.
During the outlook period I place the chance of a C class solar flare at 100%, an M class at 75% and an X class at 25%.
An earthward facing C9 or higher class solar flare can elevate the proton flux above 10 MeV (10+o) and initiate large scale high and mid latitude propagation path absorption on the AM broadcast band and 160 meters, both stateside and DX, as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds. Unfortunately even smaller C3 solar flares can create hour to hour and night to night variations in signal strength on medium frequencies.
IONOSPHERIC STORMS-
No coronal holes are currently in a geoeffective position at the moment.
During the previous 7 day outlook period, several relatively small earth facing coronal mass ejections (CMEÂ’s) did initiate repeated elevated Kp indices of 4-5.
Continued elevated Kp indices of 3-4 are probable during the new forecast period.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation. A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period elevated day and night time D layer medium frequency signal absorption tied to continued stratospheric warming should not occur.
Stratospheric warming is a major temperature change of the winter time polar and middle atmosphere from the tropopause (where the troposphere transitions into the stratosphere) to the base (D layer) of the ionosphere, lasting for many days at a time and characterized by a warming of the stratospheric temperature by some tens of degrees.
As the Stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you would not expect to see stratospheric warming effect mediumwave frequency propagation in any way BUT mediumwave frequency signals do refract off of temperature inversions and moisture discontinuities and a temperature inversion is involved with stratospheric warming. So it's possible that a mediumwave frequency signal could do any number of things when refracting off of a temperature inversion, at any height. Also stratospheric warming (STRATWARM) has an effect on the D layer by increasing radio wave absorption.
Also I've observed many times that stratospheric warming can coincide with major jetstream circulation pattern changes and movement of Arctic air from Siberian Russia across the pole to Canada and the U.S.
OUTLOOK-
Overall propagation conditions will continue to be
down 3-6 db from normal, as the medium frequencies continue a very slow recovery from depressed propagation conditions of -8 to -16 db, due to the recent elevated proton flux event of (10 +1) , as well as recent increased daily solar flux values well above 200 and intermittent Kp indices of 3-4.
Note! Increased power and good transmit and receive antennas will be helpful in overcoming the expected poor conditions.
Expect fair to good domestic propagation in both hemispheres out to approximately 3000 miles.
"High latitude" northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be fair.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3000 miles should be fair to good.
(((There will be "high" lightning induced QRN levels in south central and south eastern North America during the forecast period.)))
Occasional lightning induced QRN will also occur across the northern hemisphere, with an endless series of spring time approaching cold fronts and surface extra-tropical low pressure systems.
High to moderate tropical related lightning induced QRN will continue across equatorial regions.
Continuous high summer time related lightning induced QRN will continue to wane across the southern hemisphere, however occasional lightning induced QRN will be on the increase with an endless series of fall approaching cold fronts and surface extra-tropical low pressure systems.
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KN4LF 7 Day Medium Wave Radio Propagation Outlook Update #2002-12A Published 11:00 AM EST 02/04/10
(((NOTE!))) Though this outlook is aimed primarily at medium frequencies, it is also very applicable to HF frequencies.
Note! Due to requests from our fellow radio brethren in the international radio community I have adopted the date format of yy/mm/dd.
Solar region #9893 produced an impulsive major M8.2 flare this morning at 1231 UTC. The center of this powerful solar flare was located where the trailing magnetic delta structure is, which is currently over the central meridian. If there was a CME associated with this flare it will almost certainly be directed towards the Earth.
Per our prediction in KN4LF 7 Medium Wave Radio Propagation Outlook #2002-12 Published 2:00 PM EST 02/04/07, solar region # 9893 at N19W00 has now developed a
delta magnetic field structure and poses a threat for massive earth directed X class solar flares, coronal mass ejections and attendant disruptions of medium frequency and high frequency propagation.
Attendant propagation disruptions would be in the form of increased day and night time D absorption of transmitted signals, followed by and F layer damaging ionospheric storm.
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KN4LF 7 Day Medium Wave Radio Propagation Outlook #2002-12 Published 2:00 PM EST
02/04/07 For 02/04/08-02/04/14.
(((NOTE!))) Though this outlook is aimed primarily at medium frequencies, it
is also very applicable to HF frequencies.
Note! Due to requests from our fellow radio brethren in the international
radio community I have adopted the date format of yy/mm/dd.
PROTON FLUX-
During the outlook period the probability of an elevated proton flux event
greater then 10 MeV (10+1) is placed at 40%.
A proton flux level >10 MeV (10+1) creates increased day and night time D
layer absorption on medium wave frequencies, especially on high latitude
propagation paths but can also negatively impact mid latitudes, depending on
the intensity of the event.
((((NOTE!!! high latitude radio propagation paths may still be disturbed for
days and up to weeks, following the end of an official proton event.))))
SOLAR FLUX-
During the past 7 day outlook period the daily solar flux levels ranged
between 225 and 202.
During the outlook period the daily solar flux should range between 210 and
190.
Unfortunately there will be no important F2 layer propagation openings on 6
meters during the next 7 days, however Sporadic E (Es) and (TEQ) openings
are possible.
High solar flux values are generally considered to be detrimental to
propagation of medium wave signals both domestic and TA/TP, as more
absorption can be present via the transmitted signals' two trips through the
D layer.
Most long haul medium wave DX signals in excess of 3000 miles is via the E
Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high
solar flux values can aid in long haul medium wave propagation paths in
excess of 3000 miles, as a high solar flux value ensures a strong E and F
layer duct mechanism. However high solar activity in the form of increase
ionization created by ultraviolet and x-ray radiation can fill in the E
Valley region and interfere with the E Valley-F layer ducting mechanism. In
a sense the E Valley-F layer duct is closed and the transmitted RF signal
only propagates between the E layer and land/ocean surface, with a higher
angle and more loss.
SUNSPOT REGIONS/SOLAR FLARES/CORONAL MASS EJECTIONS-
Solar region # 9893 at N19E40, large and fast growing, now contains a beta
gamma magnetic field structure and poses a threat for large earth directed M
class solar flares and Coronal Mass Ejections. It is also possible that this
sunspot group may eventually develop a
delta magnetic field structure and poses a threat for massive earth directed
X class solar flares and Coronal Mass Ejections.
Solar regions # 9885 at N13W64 and 9887 at N03W42, also contain a beta
gamma magnetic field structure that pose a threat for large earth directed M
class solar flares and Coronal Mass Ejections.
The largest observed solar flare in the previous seven day outlook period
was an M4.9 which erupted from solar region #9885 at 02/04/04 1524 UTC,
creating an R2 shortwave fadeout (SWF) in South America, Central America and
North Atlantic regions.
Smaller M1.3, C9.7, C9.6 and C9.2 solar flares also occurred.
During the outlook period I place the chance of a C class solar flare at
100%, an M class at 60% and an X class at 10%.
An earthward facing C9 or higher class solar flare can move the proton flux
above 10 MeV (10+o) and initiate large scale high and mid latitude
propagation path absorption on the AM broadcast band and 160 meters, both
stateside and DX, as a transfer of increased density and RF signal
absorption from the day side D layer to night side of the ionosphere occurs
through high level neutral winds. Unfortunately even smaller C3 solar flares
can create hour to hour and night to night variations in signal strength on
medium frequencies.
IONOSPHERIC STORMS-
A large recurrent coronal hole arrived in geoeffective position on Thursday
02/03/28 and our planet entered it's solar wind stream on Saturday 02/03/30
This coronal hole stream initiated a prolonged period with an elevated Kp
index in the 3-4 range that finally ended on 02/04/03.
Unfortunately a small coronal hole in the southern hemisphere moved into
geoeffective position on 02/04/02 and could cause an increase in geomagnetic
activity with elevated Kp indices in the 3-5 range late by 02/04/08 UTC and
lasting for 1-3 days.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding
equatorward in magnetic latitude and generally begin have a possible
negative impact on mediumwave propagation. A Kp index of 5 or higher begins
to have a negative on high frequency shortwave propagation. However at times
skewed path propagation conditions can compensate for high latitude
propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period elevated day and night time D layer medium
frequency signal absorption tied to continued Stratospheric Warming should
not occur.
Stratospheric Warming is a major temperature change of the winter time polar
and middle atmosphere from the tropopause (where the troposphere transitions
into the stratosphere) to the base (D layer) of the ionosphere, lasting for
many days at a time and characterized by a warming of the stratospheric
temperature by some tens of degrees.
As the Stratosphere lies below the ionosphere, which is at mesosphere and
thermosphere height, you would not expect to see stratospheric warming
effect mediumwave frequency propagation in any way BUT mediumwave frequency
signals do refract off of temperature inversions and moisture
discontinuities and a temperature inversion is involved with stratospheric
warming. So it's possible that a mediumwave frequency signal could do any
number of things when refracting off of a temperature inversion, at any
height. Also stratospheric warming (STRATWARM) has an effect on the D layer
by increasing radio wave absorption.
Also I've observed many times that stratospheric warming can coincide with
major jetstream circulation pattern changes and movement of Arctic air from
Siberian Russia across the pole to Canada and the U.S.
OUTLOOK-
Overall propagation conditions will continue to be
down 3-6 db from normal as the medium frequencies continue a very slow
recovery from depressed propagation conditions of -10 to -18 db, due to the
elevated proton flux event of (10 +2) of two weeks ago, as well as recent
increased daily solar flux values above 200 and intermittent Kp indices of
3-4.
Note! Increased power and good transmit and receive antennas will be helpful
in overcoming the expected poor conditions.
Expect fair to good domestic propagation in both hemispheres out to
approximately 3000 miles.
"High latitude" northern and southern hemispheric, (TA) Trans Atlantic, (TP)
Trans Pacific and cross equatorial propagation conditions in excess of
approximately 3000 miles should be fair.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP)
Trans Pacific and cross equatorial propagation conditions in excess of
approximately 3000 miles should be fair to good.
(((There will be "high" lightning induced QRN levels in parts of North
America during the next 48-72 hours.)))
Occasional lightning induced QRN will also occur across the northern
hemisphere, with an endless series of spring time approaching cold fronts
and surface extra-tropical low pressure systems.
High to moderate tropical related lightning induced QRN will continue
across equatorial regions.
Continuous high summer time related lightning induced QRN will continue to
wane across the southern hemisphere, however occasional lightning induced
QRN will be on the increase with an endless series of fall approaching cold
fronts and surface extra-tropical low pressure systems.
Back To The Top
KN4LF 7 Medium Wave Radio Propagation Outlook #2002-11 Published 5:00 PM EST
02/03/31 For 02/04/01-02/04/07.
(((NOTE!))) Though this outlook is aimed primarily at medium frequencies, it
is also very applicable to HF frequencies.
Note! Due to requests from our fellow radio brethren in the international
radio community I have adopted the date format of yy/mm/dd.
PROTON FLUX-
During the outlook period the probability of an elevated proton flux event
greater then 10 MeV (10+1) is placed at 40%.
A proton flux level >10 MeV (10+1) creates increased day and night time D
layer absorption on medium wave frequencies, especially on high latitude
propagation paths but can also negatively impact mid latitudes, depending on
the intensity of the event.
SOLAR FLUX-
During March 2002 the daily solar flux level extremes were 208 and 165.
During the outlook period the daily solar flux should range between 185 and
215.
Unfortunately there will be no important F2 layer propagation openings on 6
meters during the next 7 days, however Sporadic E (Es) and (TEQ) openings
are probable.
High solar flux values are generally considered to be detrimental to
propagation of medium wave signals both domestic and TA/TP, as more
absorption can be present via the transmitted signals' two trips through the
D layer.
Most long haul medium wave DX signals in excess of 3000 miles is via the E
Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high
solar flux values can aid in long haul medium wave propagation paths in
excess of 3000 miles, as a high solar flux value ensures a strong E and F
layer duct mechanism. However high solar activity in the form of increase
ionization created by ultraviolet and x-ray radiation can fill in the E
Valley region and interfere with the E Valley-F layer ducting mechanism. In
a sense the E Valley-F layer duct is closed and the transmitted RF signal
only propagates between the E layer and land/ocean surface, with a higher
angle and more loss.
SUNSPOT REGIONS/SOLAR FLARES/CORONAL MASS EJECTIONS-
Solar region # 9885, large and fast growing, now contains a delta magnetic
field structure and poses a threat for massive earth directed X class solar
flares and Coronal Mass Ejections.
Solar region #'s 9884, 9886, 9887 and 9888 are magnetically complex enough
to produce isolated M-class flare activity.
The largest observed solar flare in the previous seven day outlook period
was an M3/1n which erupted from solar region #9885 at 02/03/30 1254 UTC.
Smaller C10 and C9.2 solar flares also occurred.
During the outlook period I place the chance of a C class solar flare at
100%, an M class at 75% and an X class at 25%.
An earthward facing C9 or higher class solar flare can move the proton flux
above 10 MeV (10+o) and initiate large scale high and mid latitude
propagation path absorption on the AM broadcast band and 160 meters, both
stateside and DX, as a transfer of increased density and RF signal
absorption from the day side D layer to night side of the ionosphere occurs
through high level neutral winds. Unfortunately even smaller C3 solar flares
can create hour to hour and night to night variations in signal strength on
medium frequencies.
IONOSPHERIC STORMS-
A large recurrent coronal hole arrived in geoeffective position on Thursday
02/03/28 and our planet entered it's solar wind stream on Saturday 02/03/30
This coronal hole stream initiated an elevated Kp index in the 4-5 range
yesterday evening. Elevated Kp indices in the 3-5 range can be expected
during the upcoming outlook period.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding
equatorward in magnetic latitude and generally begin have a possible
negative impact on mediumwave propagation. A Kp index of 5 or higher begins
to have a negative on high frequency shortwave propagation. However at times
skewed path propagation conditions can compensate for high latitude
propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period elevated day and night time D layer medium
frequency signal absorption tied to continued Stratospheric Warming should
not occur.
Stratospheric Warming is a major temperature change of the winter time polar
and middle atmosphere from the tropopause (where the troposphere transitions
into the stratosphere) to the base (D layer) of the ionosphere, lasting for
many days at a time and characterized by a warming of the stratospheric
temperature by some tens of degrees.
As the Stratosphere lies below the ionosphere, which is at mesosphere and
thermosphere height, you would not expect to see stratospheric warming
effect mediumwave frequency propagation in any way BUT mediumwave frequency
signals do refract off of temperature inversions and moisture
discontinuities and a temperature inversion is involved with stratospheric
warming. So it's possible that a mediumwave frequency signal could do any
number of things when refracting off of a temperature inversion, at any
height. Also stratospheric warming (STRATWARM) has an effect on the D layer
by increasing radio wave absorption.
Also I've observed many times that stratospheric warming can coincide with
major jetstream circulation pattern changes and movement of Arctic air from
Siberian Russia across the pole to Canada and the U.S.
OUTLOOK-
Overall propagation conditions will continue to be
down 2-4 db from normal as the medium frequencies continue a slow recovery
from depressed propagation conditions of -10 db, due to last weeks elevated
proton flux event of (10 +2)
but increased power and good transmit and receive antennas will be helpful
in overcoming the poorer conditions.
Expect fair to good domestic propagation in both hemispheres out to
approximately 3000 miles.
"High latitude" northern and southern hemispheric, (TA) Trans Atlantic, (TP)
Trans Pacific and cross equatorial propagation conditions in excess of
approximately 3000 miles should be fair.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP)
Trans Pacific and cross equatorial propagation conditions in excess of
approximately 3000 miles should be fair to good.
(((There will be "high" lightning induced QRN levels in parts of North
America during the next 48 hours))).
Lightning induced QRN will also occur across the northern hemisphere, with
an endless series of spring time approaching cold fronts and surface
extra-tropical low pressure systems.
High tropical related lightning induced QRN will continue across equatorial
regions.
High summer time related lightning induced QRN will continue to wane across
the southern hemisphere.
-----
KN4LF 7 Medium Wave Radio Propagation Outlook Update #2002-10A Published 10:00 AM EST 02/03/29 For 02/03/29-02/04/01.
This outlook update is issued to cover the CQ Worldwide SSB WPX Contest this weekend.
Though this outlook is aimed primarily at medium frequencies, it is also very applicable to HF frequencies.
Note! Due to requests from our fellow radio brethren in the international radio community I have adopted the date format of yy/mm/dd.
PROTON FLUX-
During the outlook period of 02/03/29-02/04/01 the proton flux should remain below 10 MeV (10+0), barring any unexpected far side of sun proton producing solar flare events.
A proton flux level >10 MeV (10+1) creates increased day and night time D layer absorption on medium wave frequencies, especially on high latitude propagation paths but can also negatively impact mid latitudes, depending on the intensity of the event.
SOLAR FLUX-
Yesterday's 2200 UTC solar flux level was 176 and during the outlook period 02/03/29-02/04/01 the daily solar flux should range between 176 and 190, barring any unexpected far or earth facing side of sun proton producing solar flare events.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signals' two trips through the D layer.
Most long haul medium wave DX signals in excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increase ionization created by ultraviolet and x-ray radiation can fill in the E Valley region and interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS/SOLAR FLARES/CORONAL MASS EJECTIONS-
Solar region # 9878 contained a delta magnetic field structure during the past 48 hours and posed a threat for earth directed X class solar flares and Coronal mass Ejections. Fortunately this solar region has decayed dramatically since yesterday but still poses a threat for propagation disrupting M class solar flare eruptions that could have dramatically curtail good propagation conditions on 160 meters in the form of elevated proton flux levels above 10 MeV (10+1) and increased D layer absorption at day and night.
Solar region #'s 9880 and 9885 are magnetically
complex enough to produce isolated M-class flare activity.
An earthward facing C9 or higher class solar flare will move the proton flux above 10o (10 MeV) and initiate large scale high latitude propagation path absorption but even smaller C4 flares are the culprit behind hour to hour and night to night variations in signal strength on the AM broadcast band and 160 meters, both stateside and DX, as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds.
IONOSPHERIC STORMS-
Generally quiet geo magnetic conditions with a Kp of 0-2 and occasional elevations to 3 will be the rule during the contest. However A large recurrent trans equatorial coronal hole arrived in geoeffective position on 02/03/28 and our planet will enter a solar wind stream flowing from the hole possibly as early as Easter Sunday the 31st. This coronal hole stream could elevate the Kp index into the 4-5 range.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation. A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
STRATOSPHERIC WARMING-
During the outlook period of 02/03/26-02/04/01 elevated day and night time D layer medium frequency signal absorption tied to continued Stratospheric Warming should not occur.
Stratospheric Warming is a major temperature change of the winter time polar and middle atmosphere from the tropopause (where the troposphere transitions into the stratosphere) to the base (D layer) of the ionosphere, lasting for many days at a time and characterized by a warming of the stratospheric temperature by some tens of degrees.
As the Stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you would not expect to see stratospheric warming effect mediumwave frequency propagation in any way BUT mediumwave frequency signals do refract off of temperature inversions and moisture discontinuities and a temperature inversion is involved with stratospheric warming. So it's possible that a mediumwave frequency signal could do any number of things when refracting off of a temperature inversion, at any height. Also stratospheric warming (STRATWARM) has an effect on the D layer by increasing radio wave absorption.
Also I've observed many times that stratospheric warming can coincide with major jetstream circulation pattern changes and movement of Arctic air from Siberian Russia across the pole to Canada and the U.S.
OUTLOOK-
Overall propagation conditions will continue be down 3-6 db as the medium frequencies continue a slow recovery from depressed propagation conditions of -10 db, due to last weeks elevated proton flux event of (10 +2)
but increased power and good transmit and receive antennas will be helpful in overcoming the poorer conditions.
Expect fair to good domestic propagation in both hemispheres out to approximately 3000 miles.
"High latitude" northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3100 miles should be fair.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3100 miles should be fair to good.
(((There will be "high" lightning induced QRN levels in parts of North America during the contest.)))
Some occasional lightning induced QRN will also occur across the northern hemisphere, with an endless series of winter time approaching cold fronts and surface extra-tropical low pressure systems.
Considerable seasonable lightning induced QRN will occur across equatorial regions and the southern hemisphere.
Back To The Top
KN4LF 7 Day Medium Wave Radio Propagation Outlook #2002-10 Published 11:00 AM
EST 02/03/24 For 02/03/26-03/04/01.
Note! Due to requests from our fellow radio brethren in the international
radio community I have adopted the date format of yy/mm/dd.
SUMMARY-
The past seven day period of 02/03/19-03/03/25 saw a continued number of
moderate M and strong C class solar flares, earth directed Coronal Mass
Ejections (CME's) and Ionospheric Storms, as the solar flux stayed below
200.
PROTON FLUX-
Continuing a trend that began during the previous week, during the outlook
period of 02/03/19-03/03/25. the proton flux moved above 10 MeV (10+0)
repeatedly (4-5 times), peaking at (10+2).
During the outlook period of 02/03/26-03/04/01 the energetic proton flux
should remain for the most part below 10 MeV (10+0), however an elevated
index above 10 MeV (10+0) may occur during the first couple of days of the
outlook period and then again towards the end of the period.
A proton flux level >10 MeV (10+1) creates elevated day and night time D
layer absorption on medium wave frequencies, especially on high latitude
propagation paths but can also negatively impact mid latitudes, depending on
the intensity of the event.
SOLAR FLUX-
During the outlook period 02/03/19-03/03/25 the daily solar flux ranged
between 188 and 170, as the "second" peak for current solar cycle 23
continues to slowly wane. This is the first 7 day period in a very long time
where the solar flux remained below 200.
During the outlook period of 02/03/26-02/04/01 the daily solar flux levels
should range between 200 and 160.
Unfortunately there will be no important F2 layer propagation openings on 6
meters during the next 7 days, however Sporadic E (Es) and (TEQ) openings
are probable.
High solar flux values are generally considered to be detrimental to
propagation of medium wave signals both domestic and TA/TP, as more
absorption can be present via the transmitted signals' two trips through the
D layer.
Most long haul medium wave DX signals in excess of 3000 miles is via the E
Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high
solar flux values can aid in long haul medium wave propagation paths in
excess of 3000 miles, as a high solar flux value ensures a strong E and F
layer duct mechanism. However high solar activity in the form of increase
ionization created by ultraviolet and x-ray radiation can fill in the E
Valley region and interfere with the E Valley-F layer ducting mechanism. In
a sense the E Valley-F layer duct is closed and the transmitted RF signal
only propagates between the E layer and land/ocean surface, with a higher
angle and more loss.
SUNSPOT REGIONS-
Solar region #9878 at N10E43 is currently the most active of the visible
regions. It continues to grow with increased area and magnetic complexity,
particularly in its trailer spots and will become the newest threat for M
class level or higher solar flares in coming days.
Solar region # 9871 is now weakening but still contains delta magnetic
fields that can produce M class level solar flares.
SOLAR FLARES-
The past seven day outlook period of 02/03/19-03/03/25 has continued active
with two M class solar flares, the largest being an M1.7 which occurred
between 1054 UTC 02/03/22 and 1154 UTC 02/03/22. Four strong C class solar
flare ranging between 9.1 and 10.0 also occurred.
During the outlook period of 02/03/26-02/04/01 I place the likelihood of a
C4 class or higher solar flare at 100%, an M5 class or higher solar flare at
40% and X1 class or higher solar flare at 05% and a proton producing solar
flare at 30%.
An earthward facing C9 or higher class solar flare will move the proton flux
above 10+o (10 MeV) and initiate large scale high latitude propagation path
absorption. Even smaller C4 flares can cause the hour to hour and night to
night variations in signal strength on the AM broadcast band and 160 meters,
both stateside and DX. as a transfer of increased density and RF signal
absorption from the day side D layer to night side of the ionosphere occurs
through high level neutral winds.
CORONAL MASS EJECTIONS-
The past seven day outlook period of 02/03/19-03/03/25 four earth directed
Coronal Mass Ejections (CME's) were hurled into space tied to the above
described solar flare events.
A Coronal Mass Ejection (CME) is the name given to an ejection of a large
amount of matter from the Sun's outer atmosphere or corona. These ejections
typically comprise millions of tons of material in the form of charged
particles, and can be seen because the material reflects sunlight. When one
of these ejections is directed towards the Earth (or conversely, directly
away from the Earth), it looks like a roughly circular "halo" surrounding
the Sun.
The "Halo CME's" then are those CME's which are more likely to impact the
Earth than those which are shot out at right angles to the Earth-Sun line.
Energetic protons emitted during CME's play a major role in increased
daytime and night time D layer absorption of mediumwave frequencies.
GEOMAGNETIC INDICES-
During the outlook 02/03/19-03/03/25 the Kp index reached a level of 5-6
three times, and a 7 once, most recently in the past 24 hours.
During the outlook period of 02/03/26-02/04/01 the Kp index should range
between 3 and 6, tied to an ionospheric storms, resulting from the most
recent earth directed Coronal Mass Ejection (CME), as well as tied to a
small coronal hole in the northern hemisphere that is in a geoeffective
position as of 02/03/24 and along lived recurrent trans-equatorial coronal
hole that will rotate into a geoeffective position on March 29-31.
As the Kp index reaches 3 or higher, the visible and invisible aurora oval
regions begin expanding equatorward in magnetic latitude and generally begin
have a possible negative impact on mediumwave propagation.
A Kp index of 5 or higher begins to have a negative on high frequency
shortwave propagation. However at times skewed path propagation conditions
can compensate for high latitude propagation path auroral absorption.
If the path over which you are communicating lies along or inside one of the
auroral ovals, you will experience degraded propagation in one of several
different forms: strong signal absorption, brief periods of strong signal
enhancement, which is mainly caused by tilts in the ionosphere that allow
signals to become focused at your location or very erratic signal behavior
in the form of strong and rapid fading, etc., caused by a variety of effects
such as multipathing, anomalous and rapid variations in absorption,
non-great-circle propagation, and polarization changes.
STRATOSPHERIC WARMING-
During the outlook period 02/03/19-02/03/25 saw little in the way of
stratospheric warming, as Arctic air movement from Siberian Russia across
the North Pole and into North America was limited.
During the outlook period of 02/03/26-02/04/01 elevated day and night time D
layer medium frequency signal absorption tied to continued Stratospheric
Warming should not occur.
Stratospheric Warming is a major temperature change of the winter time polar
and middle atmosphere from the tropopause (where the troposphere transitions
into the stratosphere) to the base (D layer) of the ionosphere, lasting for
many days at a time and characterized by a warming of the stratospheric
temperature by some tens of degrees.
As the Stratosphere lies below the ionosphere, which is at mesosphere and
thermosphere height, you would not expect to see stratospheric warming
effect mediumwave frequency propagation in any way BUT mediumwave frequency
signals do refract off of temperature inversions and moisture
discontinuities and a temperature inversion is involved with stratospheric
warming. So it's possible that a mediumwave frequency signal could do any
number of things when refracting off of a temperature inversion, at any
height. Also stratospheric warming (STRATWARM) has an effect on the D layer
by increasing radio wave absorption.
Also I've observed many times that stratospheric warming can coincide with
major jetstream circulation pattern changes and movement of Arctic air from
Siberian Russia across the pole to Canada and the U.S.
OUTLOOK-
During the recent outlook period of 02/03/19-02/03/25, medium frequency
propagation conditions were variable, with fair to at times good TA and TP
propagation conditions on the medium frequency AM broadcast band and good to
very good on 160 meters.
Some very interesting propagation conditions were observed between North
America and Europe during the past 48 hours. Early UTC on the 23rd saw
depressed high latitude medium frequency propagation conditions on the order
of 3-6 db, especially after 0500 UTC tied to elevated energetic proton
levels above 10 MeV (10+o).
Beginning at approximately 0000 UTC and peaking at approximately 0500-0600
UTC saw enhanced high latitude medium frequency propagation conditions on
the order of 3-6 db, tied to an ionospheric storm that reached a Kp level of
6. Degradation of signals then commenced at approximately 0700 UTC. The
distinctive watery, warbley auroral sound was heard on SSB propagation paths
between New England and Florida and New England and central and northern
Europe.
During the outlook period of 02/03/26-02/04/01 overall propagation
conditions will be the down some compared to the previous seven days, due to
elevated proton flux levels above 10 MeV (10+o) and a Kp index above 3,
early and then again late in the forecast period. Unfortunately lightning
induced QRN will also be on the increase as we continue to move into the
spring severe weather season.
Expect fair to good domestic propagation in both hemispheres out to
approximately 3000 miles on the MW broadcast band and good domestic
propagation on 160 meters.
High latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP)
Trans Pacific and cross equatorial propagation conditions should be poor and
at times fair on the MW broadcast band and fair to good to at times very
good on 160 meters.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP)
Trans Pacific and cross equatorial propagation conditions should be fair on
the MW broadcast band and good on 160 meters.
There will be increased lightning induced QRN in parts of North America
during the next 24-48 hours and some occasional lightning induced QRN across
the northern hemisphere, with an endless series of winter time approaching
cold fronts and surface extra-tropical low pressure systems and considerable
seasonable lightning induced QRN across equatorial regions and the southern
hemisphere.
Unfortunately the northern hemisphere is moving into the elevated QRN season
due to increased lightning producing thunderstorms. With a building El Nino
pattern the frequency of lightning producing thunderstorms will be above
normal in March and April, putting an earlier end to medium frequency DXing,
compared to Spring of 2001.
Back To The Top
KN4LF 7 Day Medium Wave Radio Propagation Outlook #2002-9 Published 9:00 PM EST 02/03/18 For 02/03/19-03/03/25.
Note! Due to requests from our fellow radio brethren in the international radio community I have adopted the date format of yy/mm/dd.
After a prolonged quiet period with fairly good to good propagation, slowly declining daily solar flux levels and sunspot counts, little in the way of important solar flare activity, no elevated proton flux levels above 10+o and a good number of days with Kp indices of 1-0, space weather activity has increased markedly during the past seven day forecast period.
PROTON FLUX-
During the outlook period of 02/03/11-02/03/17 the proton flux finally moved above 10 MeV (10+0) for the first time in quite a while.
A greater than 10+o proton event began at 17/0820 UTC and officially ended at 17/1230 UTC, but flux levels remained elevated thereafter, with a second event beginning at 18/1300 UTC. The maximum proton flux level observed so far has 25 PFU at 18/1535 UTC.
During the outlook period of 02/03/19-03/03/25 the energetic proton flux level should remain above 10 MeV (10+0), especially through the 21st.
A proton flux level >10 MeV (10+1) creates elevated day and night time D layer absorption on medium wave frequencies, especially on high latitude propagation paths, as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds.
Higher transmit output powers and good antennas can compensate for the elevated D layer absorption of medium frequency signals.
SOLAR FLUX-
During the outlook period 02/03/11-02/03/17 the daily solar flux ranged between 263 and 172, as the "second" peak of current solar cycle 23 continues to slowly wane. The 263 reading coincided with a solar flare, with the highest solar flux reading otherwise being 208.
During the outlook period of 02/03/19-02/03/25 the daily solar flux levels should range between 210 and 165.
Unfortunately there will be no important F2 layer propagation openings on 6 meters during the next 7 days, however Sporadic E (Es) openings are probable.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signals' two trips through the D layer. Most long haul medium wave DX signals in excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increase ionization created by ultraviolet and x-ray radiation can fill in the E Valley region and interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS-
Solar region #9866 at S09W46 is currently the most active of the visible regions. Though now weakening, it still contains delta magnetic fields that can produce M5 class level to even isolated X class solar flares. Another newer and rapidly growing solar region #9771 at S19E07 bears watching for future M5 or greater, maybe even X class solar flares in coming days.
SOLAR FLARES-
The past seven day outlook period has been exceptionally active with at least seven M class solar flares, the largest being an M5.7 which occurred between 0149 UTC 02/03/14 and 0239 UTC 02/03/14. Three earth directed Coronal Mass Ejections (CME's) were hurled into space tied to the M class solar flare events.
During the outlook period of 02/03/19-02/03/25 I place the likelihood of a C4 class or higher solar flare at 100%, an M5 class or higher solar flare at 60% and X1 class or higher solar flare at 30% and a proton producing solar flare at 30%.
An earthward facing M5 or higher class solar flare will move the proton flux above 10+o (10 MeV) and initiate large scale high latitude propagation path absorption. Even smaller C4 flares can cause the hour to hour and night to night variations in signal strength on the AM broadcast band and 160 meters, both stateside and DX. as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds.
GEOMAGNETIC INDICES-
During the outlook period 02/03/11-02/03/17 the Kp index reached a level of 4 several times, most recently in the past 24 hours.
During the outlook period of 02/03/19-02/03/25 the Kp index should range between 4 and 6, tied to ionospheric storms, resulting from the three recent earth directed Coronal Mass Ejections (CME's). No coronal holes are expected during the period but coronal hole development is hard to predict.
As the Kp index reaches 3 or higher, the visible and invisible aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation.
A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
If the path over which you are communicating lies along or inside one of the auroral ovals, you will experience degraded propagation in one of several different forms: strong signal absorption, brief periods of strong signal enhancement, which is mainly caused by tilts in the ionosphere that allow signals to become focused at your location or very erratic signal behavior in the form of strong and rapid fading, etc., caused by a variety of effects such as multipathing, anomalous and rapid variations in absorption, non-great-circle propagation, and polarization changes.
STRATOSPHERIC WARMING-
During the outlook period 02/03/11-02/03/17 little in the way of stratospheric warming occurred, as Arctic movement from Siberian Russia across the North Pole and into North America was limited.
During the outlook period of 02/03/19-02/03/25 elevated day and night time D layer medium frequency signal absorption, tied to Stratospheric Warming may once again increase.
Stratospheric Warming is a major temperature change of the winter time polar and middle atmosphere from the tropopause (where the troposphere transitions into the stratosphere) to the base (D layer) of the ionosphere, lasting for many days at a time and characterized by a warming of the stratospheric temperature by some tens of degrees.
As the stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you would not expect to see stratospheric warming effect mediumwave frequency propagation in any way BUT mediumwave frequency signals do refract off of temperature inversions and moisture discontinuities and a temperature inversion is involved with stratospheric warming. So it's possible that a mediumwave frequency signal could do any number of things when refracting off of a temperature inversion, at any height. Also stratospheric warming (STRATWARM) has an effect on the D layer by increasing radio wave absorption.
Also I've observed many times that stratospheric warming can coincide with major jetstream circulation pattern changes and movement of Arctic air from Siberian Russia across the pole to Canada and the U.S.
OUTLOOK-
During the outlook period of 02/03/19-02/03/25 overall propagation conditions will be the down some compared to the previous seven days, due to elevated proton flux levels above 10+0 and a Kp index above 3. Unfortunately lightning induced QRN will also be on the increase as we continue to move into the spring severe weather season.
Expect fair to good domestic propagation in both hemispheres out to approximately 3000 miles on the MW broadcast band and good domestic propagation on 160 meters.
High latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions should be poor and at times fair on the MW broadcast band and fair to good on 160 meters.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions should be fair on the MW broadcast band and good on 160 meters.
There will be high lightning induced QRN in parts of North America during the next 48-72 hours and some occasional lightning induced QRN across the northern hemisphere, with an endless series of winter time approaching cold fronts and surface extra-tropical low pressure systems and considerable seasonable lightning induced QRN across equatorial regions and the southern hemisphere.
Unfortunately the northern hemisphere is moving into the elevated QRN season due to increased lightning producing thunderstorms. With a building El Nino pattern the frequency of lightning producing thunderstorms will be above normal in March and April, putting an earlier end to medium frequency DXing, compared to Spring of 2001.
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KN4LF 7 Day Medium Wave Radio Propagation Outlook Update #2002-8B Published 11:00 PM EST 02/03/16.
Twisted delta magnetic fields above sunspot group #9866 erupted at 2315 UTC on 02/03/15. This blast sparked a 12-hour-long M2+class solar flare and hurled a full-halo (CME) coronal mass ejection toward Earth. This rapidly expanding cloud will likely sweep past our planet late Sunday or Monday UTC. Sky watchers should be alert for brilliant visible auroras especially during the hours around local midnight. This imminent event will be the most significant in many months, with the Kp index rising to as high as a 7. The proton flux level has already reached >10 MeV (10+1) level.
An earthward facing M or higher class solar flare will move the proton flux above 10o (10 MeV) and initiate large scale high latitude propagation path absorption. Even smaller C4 flares can cause the hour to hour and night to night variations in signal strength on the AM broadcast band and 160 meters, both stateside and DX. as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds.
An earthward facing solar flare can also emit a (CME) Coronal Mass Ejection with can create an Ionospheric Storm (elevated Kp index) and visible Aurora Displays.
As the Kp index reaches 3 or higher, the visible and invisible aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation.
A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
If the path over which you are communicating lies along or inside one of the auroral ovals, you will experience degraded propagation in one of several different forms: strong signal absorption, brief periods of strong signal enhancement, which is mainly caused by tilts in the ionosphere that allow signals to become focused at your location or very erratic signal behavior in the form of strong and rapid fading, etc., caused by a variety of effects such as multipathing, anomalous and rapid variations in absorption, non-great-circle propagation, and polarization changes.
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KN4LF 7 Day Medium Wave Radio Propagation Outlook Update #2002-8A Published 11:00 PM EST 02/03/11.
Newly emerged sunspot group #9866 continues to grow in magnetic complexity and size, and now spans an area equal to five planet Earths. It now has a delta class twisted magnetic field that harbors energy for huge and devastating X-class solar flares.
No X class level solar flares have occurred since 12/28/01.
An earthward facing M5 or higher class solar flare will move the proton flux above 10o (10 MeV) and initiate large scale high latitude propagation path absorption. Even smaller C4 flares can cause the hour to hour and night to night variations in signal strength on the AM broadcast band and 160 meters, both stateside and DX, as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds.
An earthward directed solar flare can also emit a (CME) Coronal Mass Ejection, with can create an Ionospheric Storm (elevated Kp index) and visible Aurora Displays.
As the Kp index reaches 3 or higher, the visible and invisible aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation.
A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
If the path over which you are communicating lies along or inside one of the auroral ovals, you will experience degraded propagation in one of several different forms: strong signal absorption, brief periods of strong signal enhancement, which is mainly caused by tilts in the ionosphere that allow signals to become focused at your location or very erratic signal behavior in the form of strong and rapid fading, etc., caused by a variety of effects such as multipathing, anomalous and rapid variations in absorption, non-great-circle propagation, and polarization changes.
High lightning induced QRN will also occur in the eastern 2/3's of North America during the next 24-48 hours.
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KN4LF 7 Day Medium Wave Radio Propagation Outlook #2002-8 Published 11:00 AM EST 02/03/10 For 02/03/11-02/03/17.
Note! Due to requests from our fellow radio brethren in the international radio community I have adopted the date format of yy/mm/dd.
PROTON FLUX-
During the outlook period of 02/03/04-02/03/10 the proton flux should remained below 10 MeV (10+0).
During the outlook period of 02/03/11-02/03/17 the proton flux should remain below 10 MeV (10+0), barring any unexpected near side or far side sun proton producing solar flare events.
A proton flux level >10 MeV (10+1) creates elevated day and night time D layer absorption on medium wave frequencies, especially on high latitude propagation paths.
SOLAR FLUX-
During the outlook period 02/03/03-02/03/10 the daily solar flux ranged between 208 and 172, as the “second” peak for current solar cycle 23 continues to slowly wane.
During the outlook period of 02/03/11-02/03/17 the daily solar flux levels should range between 210 and 170.
Unfortunately there will be no important F2 layer propagation openings on 6 meters during the next 7 days, however Sporadic E (Es) openings are probable.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signalsÂ’ two trips through the D layer. Most long haul medium wave DX signals in excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increase ionization created by ultraviolet and x-ray radiation can fill in the E Valley region and interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS-
Solar region #9866 at S10E73 is currently the most active of the visible regions. It contains beta gamma magnetic fields that can produce M class level solar flares and should continue grow in size and complexity.
SOLAR FLARES-
The past seven day outlook period has been exceptionally quiet with few flares of any importance until the 9th. During the outlook period 02/03/03-02/03/10 the largest solar flare events were an M2.6/1F at 1856 UTC and an M1.3/1F event at 2210 UTC on the 9th.
During the outlook period of 02/03/11-02/03/17 I place the likelihood of a C4 class or higher solar flare at 100%, an M5 class or higher solar flare at 40% and X1 class or higher solar flare at 20% and a proton producing solar flare at 10%.
An earthward facing M5 or higher class solar flare will move the proton flux above 10o (10 MeV) and initiate large scale high latitude propagation path absorption. Even smaller C4 flares can cause the hour to hour and night to night variations in signal strength on the AM broadcast band and 160 meters, both stateside and DX. as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds.
GEOMAGNETIC INDICES-
During the outlook period 02/02/03-02/03/10 the Kp index reached a level of 4 six times, due to a large re-occurring geo-effective (earth facing) coronal hole. Visible Aurora displays did occur.
During the outlook period of 02/03/11-02/03/17 the Kp index should range between 3-4 due to as yet unobserved effective (earth facing) coronal holes.
As the Kp index reaches 3 or higher, the visible and invisible aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation.
A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
If the path over which you are communicating lies along or inside one of the auroral ovals, you will experience degraded propagation in one of several different forms: strong signal absorption, brief periods of strong signal enhancement, which is mainly caused by tilts in the ionosphere that allow signals to become focused at your location or very erratic signal behavior in the form of strong and rapid fading, etc., caused by a variety of effects such as multipathing, anomalous and rapid variations in absorption, non-great-circle propagation, and polarization changes.
STRATOSPHERIC WARMING-
During the outlook period 02/03/03-02/03/10 extensive stratospheric warming occurred, as Arctic air was on the move from Siberian Russia across the north pole and into North America.
During the outlook period of 02/03/11-02/03/17 elevated day and night time D layer medium frequency signal absorption tied to continued Stratospheric Warming will diminish.
This is what my government forecasting brethren had to say about the most recent Strat Warm alert: Stratwarm Alert Exists Stratwarm Saturday Comment: Throughout the stratosphere, disturbed circulation pattern with the warm air over the Polar region and Eastern Asia and a displaced vortex over Northern Siberia, leading to a reversed temperature gradient between 60N and the Pole from 100 to 2HPa and weak mean zonal easterly winds at 60N at 3 and 2HPa.
Stratospheric Warming is a major temperature change of the winter time polar and middle atmosphere from the tropopause (where the troposphere transitions into the stratosphere) to the base (D layer) of the ionosphere, lasting for many days at a time and characterized by a warming of the stratospheric temperature by some tens of degrees.
As the stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you would not expect to see stratospheric warming effect mediumwave frequency propagation in any way BUT mediumwave frequency signals do refract off of temperature inversions and moisture discontinuities and a temperature inversion is involved with stratospheric warming. So it's possible that a mediumwave frequency signal could do any number of things when refracting off of a temperature inversion, at any height. Also stratospheric warming (STRATWARM) has an effect on the D layer by increasing radio wave absorption.
Also I've observed many times that stratospheric warming can coincide with major jetstream circulation pattern changes and movement of Arctic air from Siberian Russia across the pole to Canada and the U.S.
OUTLOOK-
During the outlook period of 02/03/11-02/03/17 overall propagation conditions will be the best of the DX season so far. Unfortunately lightning induced QRN will also be on the increase as we move into the spring severe weather season.
Expect good domestic propagation in both hemispheres out to approximately 3000 miles on the MW broadcast band and 160 meters.
High latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions should be fair and at times good on the MW broadcast band and good to at times very good on 160 meters.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions should be good on the MW broadcast band and very good on 160 meters.
There will be high lightning induced QRN in parts of North America during the next 24 hours and some occasional lightning induced QRN across the northern hemisphere, with an endless series of winter time approaching cold fronts and surface extra-tropical low pressure systems and considerable seasonable lightning induced QRN across equatorial regions and the southern hemisphere.
Unfortunately the northern hemisphere is moving into the elevated QRN season due to increased lightning producing thunderstorms. With a building El Nino pattern the frequency of lightning producing thunderstorms will be above normal in March and April, putting an earlier end to medium frequency DXing, compared to Spring of 2001.
Back To The Top
KN4LF 7 Day Medium Wave Radio Propagation Outlook #2002-7 Published 11:00 AM EST 02/03/10 For 02/03/11-02/03/17
Note! Due to requests from our fellow radio brethren in the international radio community I have adopted the date format of yy/mm/dd.
Per our forecast medium frequency propagation for the ARRL Worldwide DX Contest this past weekend was good, unfortunately our high lightning induced QRN level forecast also verified in North America.
PROTON FLUX-
During the outlook period of 02/02/25-02/03/03 the proton flux should remained below 10 MeV (10+0).
During the outlook period of 02/03/04-02/03/10 the proton flux should remain below 10 MeV (10+0), barring any unexpected near side or far side sun proton producing solar flare events.
A proton flux level >10 MeV (10+1) creates elevated D absorption on medium wave frequencies, especially on high latitude propagation paths.
SOLAR FLUX-
During the outlook period 02/02/25-02/03/03 the daily solar flux ranged between 211 and 186. For February the daily solar flux values ranged from 257 and 188, as the “second” peak for current solar cycle 23 continues to slowly wane.
During the outlook period of 02/03/04-02/03/10 the daily solar flux levels should range between 215 and 180.
Unfortunately there will be no important F2 layer propagation openings on 6 meters during the next 7 days, however Sporadic E (Es) openings are probable.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signalsÂ’ two trips through the D layer. Most long haul medium wave DX signals in excess of 3000 miles is via the E Valley-F layer ducting and/or Chordal Hop propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increase ionization created by ultraviolet and x-ray radiation can fill in the E Valley region and interfere with the E Valley-F layer ducting mechanism. In a sense the E Valley-F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS-
Solar region #‘s 9844 and 9845 are currently the most active of the visible regions. They contain beta gamma magnetic fields that can produce M class level solar flares.
SOLAR FLARES-
During the outlook period 02/02/25-02/03/03 the largest solar flare events were an M2 at 0010 UTC on the 28th and an M1 event at 1555 UTC on the 27th.
During the outlook period of 02/03/04-02/03/10 I place the likelihood of a C4 class or higher solar flare at 100%, an M5 class or higher solar flare at 30% and X1 class or higher solar flare at 10% and a proton producing solar flare at 5%.
An earthward facing M5 or higher class solar flare will move the proton flux above 10o (10 MeV) and initiate large scale high latitude propagation path absorption. Even smaller C4 flares can cause the hour to hour and night to night variations in signal strength on the AM broadcast band and 160 meters, both stateside and DX. as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds.
GEOMAGNETIC INDICES-
During the outlook period 02/02/25-02/03/03 the Kp index reached a level of 4-5 between 0900-2100 UTC the 28th.
During the outlook period of 02/03/04-02/03/10 the Kp index should range between 4-6 due to a large geo-effective (earth facing) coronal hole. The Ionospheric Storm should begin on UTC Monday the 4th and visible Aurora activity is probable.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation.
A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
If the path over which you are communicating lies along or inside one of the auroral ovals, you will experience degraded propagation in one of several different forms: strong signal absorption, brief periods of strong signal enhancement, which is mainly caused by tilts in the ionosphere that allow signals to become focused at your location or very erratic signal behavior in the form of strong and rapid fading, etc., caused by a variety of effects such as multipathing, anomalous and rapid variations in absorption, non-great-circle propagation, and polarization changes.
STRATOSPHERIC WARMING-
During the outlook period 02/02/25-02/03/03 extensive stratospheric warming occurred, as Arctic air was on the move from Siberian Russia across the north pole and into North America. This Arctic cold hit Florida with minimum temperatures of 14 deg and 19 deg. occurring on the 2/28 and 3/1.
During the outlook period of 02/03/04-02/03/10 elevated day and night time D layer medium frequency signal absorption tied to continued Stratospheric Warming is will continue, with continued Arctic cold at times invading the eastern 2/3Â’s of the U.S.
As the stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you might not normally expect to see stratospheric warming effect the AM broadcast band and 160 meter propagation in any way BUT mediumwave frequency signals do refract off of temperature inversions and moisture discontinuities and temperature and moisture inversions are involved with stratospheric warming. So it's possible that a mediumwave signal could do any number of things when refracting off of a temperature inversion, at any height.
Just as the E layer is the main refraction medium for medium wave signal propagation within approximately 3100 miles, so is Sporadic E (Es). Like stratospheric level warming and tropospheric level temperature and moisture discontinuities, Sporadic E can depending on the circumstances absorb, block and refract medium wave RF signals in an unpredictable manner.
OUTLOOK-
During the outlook period of 02/03/04-02/03/10 overall propagation conditions will be down a little compared with the past two weeks but increased power and good transmit and receive antennas will be helpful in overcoming the slightly poorer conditions.
Expect good domestic propagation in both hemispheres out to approximately 3000 miles on the MW broadcast band and 160 meters.
High latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions should be poor and at times fair on the MW broadcast band and fair to at times good on 160 meters.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions should be fair on the MW broadcast band and good on 160 meters.
There will be high lightning induced QRN in parts of North America during the next 24 hours and some occasional lightning induced QRN across the northern hemisphere, with an endless series of winter time approaching cold fronts and surface extra-tropical low pressure systems and considerable seasonable lightning induced QRN across equatorial regions and the southern hemisphere.
Unfortunately the northern hemisphere is moving into the elevated QRN season due to increased lightning producing thunderstorms. With a building El Nino pattern the frequency of lightning producing thunderstorms will be above normal in March and April, putting an earlier end to medium frequency Dxing, compared to Spring of 2001.
Back To The Top
KN4LF 7 Medium Wave Radio Propagation Outlook #2002-6B Published 10:00 AM EST 02/03/01 For 02/03/01-02/03/03.
This outlook update is issued to cover the ARRL Worldwide DX Contest.
PROTON FLUX-
During the outlook period of 02/03/01-02/03/03 the proton flux should remain below 10 MeV (10+0), barring any unexpected far side of sun proton producing solar flare events.
A proton flux level >10 MeV (10+1) creates elevated D absorption on medium wave frequencies.
SOLAR FLUX-
Todays solar flux level is 204 and during the outlook period 02/03/01-02/03/03 the daily solar flux should range between 205 and 215.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signals two trips through the D layer. Most long haul medium wave DX signals in excess of 3000 miles is via the E/F layer ducting and/or E valley propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increase ionization created by ultraviolet and x-ray radiation can fill in the E Valley region and interfere with the E/F layer ducting mechanism. In a sense the E/F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SOLAR FLARES-
Solar regions #‘s 9839 and 9842 contain beta gamma field structures that pose a threat for earth directed M5-class solar flares, that would dramatically curtail recent good propagation conditions on 160 meters in the form of elevated proton flux levels above 10 MeV (10+1) and increased D layer absorption at day and night. Fortunately these regions will rotate around the Sun's NW limb shortly.
An earthward facing M5 or higher class solar flare will move the proton flux above 10o (10 MeV) and initiate large scale high latitude propagation path absorption but even smaller C4 flares are the culprit behind hour to hour and night to night variations in signal strength on the AM broadcast band and 160 meters, both stateside and DX, as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds.
STRATOSPHERIC WARMING-
Elevated day and night time D layer signal absorption tied to continued Stratospheric Warming is still occurring and will continue.
IONOSPHERIC STORMS-
A large geo-effective (earth facing) coronal hole has been the culprit behind elevated Kp indices to 5 and occasional elevated Kp indices above 3 will continue through the weekend.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation. A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation. However at times skewed path propagation conditions can compensate for high latitude propagation path auroral absorption.
OUTLOOK-
Overall propagation conditions will be down some compared with the past 7 days but increased power and good transmit and receive antennas will be helpful in overcoming the poorer conditions.
Expect good domestic propagation in both hemispheres out to approximately 3000 miles.
"High latitude" northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3100 miles should be fair.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3100 miles should be good.
There will be "high" lightning induced QRN levels in parts of North America.
Some occasional lightning induced QRN will also occur across the northern hemisphere, with an endless series of winter time approaching cold fronts and surface extra-tropical low pressure systems.
Considerable seasonable lightning induced QRN will occur across equatorial regions and the southern hemisphere.
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KN4LF 7 Medium Wave Radio Propagation Outlook #2002-6 Published 11:00 AM EST 02/02/25 For 02/02/25-02/03/03.
Note! Due to requests from our fellow radio brethren in the international radio community I have adopted the date format of yy/mm/dd.
PROTON FLUX-
During the period of 02/02/25-02/03/03 the proton flux should remain below 10 MeV (10+0), barring any unexpected proton producing solar flare events.
A proton flux level >10 MeV (10+1) creates elevated D absorption on medium wave frequencies.
SOLAR FLUX-
During the past 7 days daily solar flux values ranged between 208 and 188. So far during the first 24 days of February 2002 the daily solar flux has ranged between 257 and 188. Our second peak in solar cycle #23 continues to slowly wane.
During the outlook period the daily solar flux should range between 225 and 185.
The expected daily solar flux values will not support long haul F2 openings on 6 meters but medium haul Sporadic E (Es) propagation is probable.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signals two trips through the D layer. Most long haul medium wave DX signals in excess of 3000 miles is via the E/F layer ducting and/or E valley propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increase ionization created by ultraviolet and x-ray radiation can fill in the E Valley region and interfere with the E/F layer ducting mechanism. In a sense the E/F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS-
Solar region #9830 located at S17w64 is currently the most active of the visible regions. It currently still contains weakening twisted delta class magnetic fields which would harbor isolated potential for huge X1 class or higher proton solar flares.
All other solar regions are quiet and stable or slowly growing or decaying at this moment.
SOLAR FLARES-
I place the likelihood of a C4 class or higher solar flare at 100%, an M5 class or higher solar flare at 40% and X1 class or higher solar flare at 20% and a proton producing solar flare at 10% during the upcoming 7 day outlook period.
An earthward facing M5 or higher class solar flare will move the proton flux above 10o (10 MeV) and initiate large scale high latitude propagation path absorption but even smaller C4 flares are the culprit behind hour to hour and night to night variations in signal strength on the AM broadcast band and 160 meters, both stateside and DX. as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds.
GEOMAGNETIC INDICES-
There are currently two obvious small coronal holes in geoeffective positions and are the source of the present elevated Kp values.
Further elevation of the Kp index to 3 is possible from future developing coronal holes during the 7 day outlook period.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation. A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation.
If the path over which you are communicating lies along or inside one of the auroral ovals, you will experience degraded propagation in one of several different forms: strong signal absorption, brief periods of strong signal enhancement, which is mainly caused by tilts in the ionosphere that allow signals to become focused at your location or very erratic signal behavior in the form of strong and rapid fading, etc., caused by a variety of effects such as multipathing, anomalous and rapid variations in absorption, non-great-circle propagation, and polarization changes.
STRATOSPHERIC WARMING-
Stratospheric warming has been occurring for the past several days and more is expected during the 7 day outlook period, as Arctic air has been and continues to be on the move across the north pole from Siberian Russia to North America. Some continued elevated D layer absorption of signals caused by the stratospheric warming will occur.
As the stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you might not normally expect to see stratospheric warming effect the AM broadcast band and 160 meter propagation in any way BUT mediumwave frequency signals do refract off of temperature inversions and moisture discontinuities and temperature and moisture inversions are involved with stratospheric warming. So it's possible that a mediumwave signal could do any number of things when refracting off of a temperature inversion, at any height.
Just as the E layer is the main refraction medium for medium wave signal propagation within approximately 3100 miles, so is Sporadic E (Es). Like stratospheric level warming and tropospheric level temperature and moisture discontinuities, Sporadic E can depending on the circumstances absorb, block and refract medium wave RF signals in an unpredictable manner.
OUTLOOK-
The bottom line for the next 7 days? The best overall band conditions for propagation of medium wave signals so far this season.
Expect good domestic propagation in both hemispheres on the AM broadcast band and good to excellent propagation on 160 meters out to approximately 3000 miles.
High latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions should be fair on the AM broadcast band and good on 160 meters, barring any sudden elevated proton event from an Earth facing or diffuse far side of Sun solar flare or newly developed coronal hole.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions should be good on the AM broadcast band and very good on 160 meters, barring any sudden elevated proton event from an Earth facing or diffuse far side of Sun solar flare or newly developed coronal hole.
Most stateside AM broadcast band frequencies will contain co-channel North and Central/South American stations, with northern latitude stations dominating at times.
There will be some occasional lightning induced QRN in parts of North America and the northern hemisphere in general, with an endless series of winter time approaching cold fronts and surface extra-tropical low pressure systems and considerable seasonable lightning induced QRN across equatorial regions and the southern hemisphere.
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KN4LF 7 Medium Wave Radio Propagation Outlook #2002-5B Published 10:00 AM EST 02/02/22 For 02/02/22-02/02/24.
This outlook update is issued to cover the CQ Worldwide 160 Meter Phone Contest.
Nine moderate sized M class solar flare events were recorded on February 20 and 21st!
Twisted magnetic fields above sunspot group #9825 erupted several times on Feb. 20th sparking an M5.1/1N class solar flare at 02/02/20/0612 UT, which hurled a (CME) coronal mass ejection toward Earth that will sweep past our planet on Friday or Saturday, creating an elevated K index of 4-6 and increased aurora related high latitude propagation path absorption and unpredictable refraction. As the CME arrives some temporary enhanced high latitude propagation is possible.
Active sunspot region #9830 still contains a delta-class magnetic field structure and still poses a threat for earth directed X-class solar flares that would dramatically curtail recent good propagation conditions on 160 meters in the form of elevated proton flux levels above 10 MeV (10+1) and increased D layer absorption at day and night. However the threat of an X class flare is diminishing as the region is now in a weakening phase.
Elevated D layer signal absorption tied to continued Stratospheric Warming is still occurring.
OUTLOOK-
Overall propagation conditions will be down some compared with the past 7 days but increased power and good transmit and receive antennas will be helpful in overcoming the poorer conditions.
Expect good domestic propagation in both hemispheres out to approximately 3000 miles.
High latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions should be fair.
Mid latitude northern and southern hemispheric, (TA) Trans Atlantic, (TP) Trans Pacific and cross equatorial propagation conditions should be good.
There will be high lightning induced QRN in parts of North America and some occasional lightning induced QRN across the northern hemisphere, with an endless series of winter time approaching cold fronts and surface extra-tropical low pressure systems and considerable seasonable lightning induced QRN across equatorial regions and the southern hemisphere.
Back To The Top
KN4LF 7 Medium Wave Radio Propagation Outlook #2002-5A Published 11:00 AM EST 02/02/20.
Note! Due to requests from our fellow radio brethren in the international
radio community I have adopted the date format of yy/mm/dd.
Active and rapidly growing sunspot region #9830 developed a delta-class
magnetic field during the past 24 hours and poses a threat for earth
directed X-class solar flares that would dramatically curtail recent good
propagation conditions on 160 meters.
The proton flux level climbed to >10 MeV (10+1) at 0300 UTC 02/02/20 and the
Kp index climbed to 3 at 0600 UTC 02/02/20, as a series of M3-5 class solar
flares occurred between 0000-0900 UTC 02/02/20, associated with sunspot
region #9830.
Increased daytime and nighttime D layer absorption of medium frequency
signals caused by the stratospheric warming is also once again occurring, as
Arctic air has begun moving again across the north pole from Siberian Russia
into North America.
North America is now moving into a weather pattern that may produce the
coldest weather of the current winter, during the next 3-4 week period.
Also a continued increase in night time lightning induced QRN will occur
during the next 24-48 hours across portions of North America.
A proton flux level >10 MeV (10+1) creates elevated day and night time D
absorption on medium wave frequencies including 160 meters.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding
equatorward in magnetic latitude and generally begin have a possible
negative impact on mediumwave propagation. A Kp index of 5 or higher begins
to have a negative on high frequency shortwave propagation.
-----
KN4LF 7 Medium Wave Radio Propagation Outlook #2002-5 Published 11:00 PM EST 02/02/17 For 02/02/18-02/02/24
Note! Due to requests from our fellow radio brethren in the international radio community I have adopted the date format of yy/mm/dd.
PREVIOUS FORECAST VERIFICATION-
Per my propagation outlook update #4A issued for the ARRL International CW contest for the weekend of the 16-17th, I called for some temporarily enhanced high latitude path propagation on Saturday February 16 UTC followed by degraded high latitude path propagation conditions on Sunday February 17 UTC, due to a likely elevated Kp index of 4-6. This outlook did verify.
Per my previous outlook #4 issued at 8:00 AM EST 02/02/10 For 02/02/11-02/02/17, medium wave propagation conditions were good with some strong signals arriving in North America from Europe in the evenings and from Oceania in the early morning period.
Per my previous outlook the proton flux remained below 10 MeV (10+0).
Per my previous outlook I forecasted the daily solar flux level to exceed 250 but it only reached 217 on the 02/02/10.
Per my previous outlook I placed the likelihood of a C4 class or higher solar flare at 100%, an M5 class or higher solar flare at 70% and X1 class or higher solar flare at 20%, during the upcoming 7 day outlook period. The largest solar flare solar flare to occur was a C9 which occurred 02/02/13 at 0600 UTC.
Per my previous outlook I forecasted the Kp index to reach between 3 and 5. The Kp index reached 4 on 02/02/17 at 0900 UTC.
PROTON FLUX-
During the period of 02/02/18-02/02/24 the proton flux should remain below 10 MeV (10+0).
A proton flux level >10 MeV (10+1) creates elevated D absorption on medium wave frequencies.
SOLAR FLUX-
During the past 7 days daily solar flux values ranged between 217 and 191. So far during the first 17 days of February 2002 the daily solar flux has ranged between 257 and 191. Our second peak in solar cycle # 23 continues to slowly wane.
During the outlook period the daily solar flux should bottom out around 190 and then begin climbing towards 225.
The daily expected solar flux peak will support only isolated long haul F2 openings on 6 meters but medium haul Sporadic E (Es) propagation is probable.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signals two trips through the D layer. Most long haul medium wave DX signals in excess of 3000 miles is via the E/F layer ducting and/or E valley propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increase ionization created by ultraviolet and x-ray radiation can fill in the E Valley region and interfere with the E/F layer ducting mechanism. In a sense the E/F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more loss.
SUNSPOT REGIONS-
No solar regions currently contain twisted delta class magnetic fields which would harbor potential for huge X1 class proton solar flares.
Solar region #9830 located at S18E31 is currently the most active of the visible regions. It has produced occasional lesser C class flares as it has grown in magnetic complexity. A magnetic delta configuration has developed and is capable of isolated M4 class or lower proton solar flares in coming days.
All other solar regions are quiet and stable or slowly growing or decaying at this moment.
SOLAR FLARES-
I place the likelihood of a C4 class or higher solar flare at 100%, an M5 class or higher solar flare at 40% and X1 class or higher solar flare at 10%, during the upcoming 7 day outlook period.
An earthward facing M5 or higher class solar flare will move the proton flux above 10o (10 MeV) and initiate large scale high latitude propagation path absorption but even smaller C4 flares are the culprit behind hour to hour and night to night variations in signal strength on the AM broadcast band and 160 meters, both stateside and DX. as a transfer of increased density and RF signal absorption from the day side D layer to night side of the ionosphere occurs through high level neutral winds.
GEOMAGNETIC INDICES-
There are no obvious coronal holes approaching geoeffective positions.
Renewed elevation of the Kp index to 3 is possible from future developing coronal holes during the 7 day outlook period.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding equatorward in magnetic latitude and generally begin have a possible negative impact on mediumwave propagation. A Kp index of 5 or higher begins to have a negative on high frequency shortwave propagation.
If the path over which you are communicating lies along or inside one of the auroral ovals, you will experience degraded propagation in one of several different forms: strong signal absorption, brief periods of strong signal enhancement, which is mainly caused by tilts in the ionosphere that allow signals to become focused at your location or very erratic signal behavior in the form of strong and rapid fading, etc., caused by a variety of effects such as multipathing, anomalous and rapid variations in absorption, non-great-circle propagation, and polarization changes.
STRATOSPHERIC WARMING-
There is currently no stratospheric warming taking place and none is expected during the 7 day outlook period. However if Arctic air unexpectedly goes on the move again in coming days across the north pole from Siberian Russia to North America during the period, some increased D layer absorption of signals caused by the stratospheric warming will occur. Sporadic E (Es) propagation is also possible.
As the stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you might not normally expect to see stratospheric warming effect the AM broadcast band and 160 meter propagation in any way BUT mediumwave frequency signals do refract off of temperature inversions and moisture discontinuities and temperature and moisture inversions are involved with stratospheric warming. So it's possible that a mediumwave signal could do any number of things when refracting off of a temperature inversion, at any height.
Just as the E layer is the main refraction medium for medium wave signal propagation within approximately 3100 miles, so is Sporadic E (Es). Like stratospheric level warming and tropospheric level temperature and moisture discontinuities, Sporadic E can depending on the circumstances absorb, block and refract medium wave RF signals in an unpredictable manner.
OUTLOOK-
The bottom line for the next 7 days? A continuation of the best overall band conditions for propagation of medium wave signals so far this season.
Expect good domestic propagation in both hemispheres on the AM broadcast band and good to excellent propagation on 160 meters out to approximately 3000 miles.
High latitude northern hemispheric, (TA) Trans Atlantic, TP) Trans Pacific and cross equatorial propagation conditions should be fair on the AM broadcast band and good on 160 meters, barring any sudden elevated proton event from an Earth facing or diffuse far side of Sun solar flare or newly developed coronal hole.
Most stateside AM broadcast band frequencies will contain co-channel North and Central/South American stations, with northern latitude stations dominating at times.
There will also be some occasional lightning induced QRN across the northern hemisphere, with an endless series of winter time approaching cold fronts and surface extra-tropical low pressure systems and considerable seasonable lightning induced QRN across the southern hemisphere.
Back To The Top
KN4LF 7 Medium Wave Radio Propagation Outlook #2002-4A Published 8:00 AM EST 02/02/15
The daily solar flux value has dropped below 200 and sits at 196. Solar flux values may remain below 200 for the next several days. The lower the solar flux level is below 200 the better the propagation conditions on medium wave frequencies, in general.
The largest solar flare so far during the present forecast period is a C9 which occurred 02/02/13 at 0600 UTC.
A filament eruption was observed in the southwest quadrant of the sun late on the evening of February 13 into early February 14. This event produced a full halo earthward bound Coronal Mass Ejection(CME) which is likely to impact the Earth on February 16 UTC, in the form of an elevated Kp index of 4-6.
Per our outlook issued at 8:00 AM EST 02/02/10 For 02/02/11-02/02/17, medium wave propagation conditions have been good the past several days, with some strong signals arriving in North America from Europe in the evenings and from Oceania in the early morning period.
Our propagation forecast for the ARRL International CW contest this weekend calls for some temporarily enhanced high latitude path propagation on Saturday February 16 UTC followed by degraded high latitude path propagation conditions on Sunday February 17 UTC, due to a likely elevated Kp index of 4-6.
-----
KN4LF 7 Medium Wave Radio Propagation Outlook #2002-4 Published 8:00 AM EST 02/02/10 For 02/02/11-02/02/17
Note! Due to requests from our fellow radio brethren in the international
radio community I have adopted the date format of yy/mm/dd.
PREVIOUS FORECAST VERIFICATION-
Sorry for the delay in producing and publishing outlook #4, I was ill. As
there was a gap in my outlook between 02/01/28 and 02/02/10 I will skip the
detailed forecast verification this time but outlook # 3 did verify.
PROTON FLUX-
During the period of 02/01/25 through 02/02/10 the proton flux level peaked
briefly at >10 MeV (10+1) on 02/01/27/1200 UTC. Otherwise it remained below
10 MeV (10+0).
A proton flux level > 10 MeV (10+1) creates elevated D absorption on medium
wave frequencies.
SOLAR FLUX-
During the month of January 2002 daily solar flux values ranged between 261
and 188. So far during the first 10 days of February 2002 the daily solar
flux has ranged between 257 and 191. Our second peak in solar cycle # 23
continues.
The daily solar flux peaks above 250 during the first 40 days of 2002 did
aid in occasional excellent F2 openings on 6 meters.
Yesterdays solar flux level was 217, after bottoming out at 191 on the
February 7th, only the second time below 200 since August 7th, 2001. A daily
solar flux peak as high as 250+ is possible in intervening 7 days, which
would be bad for 160 meter ops. But a boon to 6 meters ops. looking for
global F2 propagation openings. Though generally considered to be out of
season, Sporadic E (Es) openings have also been occurring and more openings
are probable during the outlook period.
High solar flux values are generally considered to be detrimental to
propagation of medium wave signals both domestic and TA/TP, as more
absorption can be present via the transmitted signals two trips through the
D layer. Most long haul medium wave DX signals in excess of 3000 miles is
via the E/F layer ducting and/or E valley propagation modes. Therefore high
solar flux values can aid in long haul medium wave propagation paths in
excess of 3000 miles, as a high solar flux value ensures a strong E and F
layer duct mechanism. However high solar activity in the form of increase
ionization created by ultraviolet and x-ray radiation can fill in the E
Valley region and interfere with the E/F layer ducting mechanism. In a sense
the E/F layer duct is closed and the transmitted RF signal only propagates
between the E layer and land/ocean surface, with a higher angle and more
loss.
SUNSPOT REGIONS-
No solar regions currently contain twisted delta class magnetic fields which
would harbor potential for huge X1 class proton solar flares and our best
bet for smaller but still significant M5 class or higher proton solar flares
in coming days will be with solar region #'s 9811, 9821 and 9825.
Solar region #9821 is growing rapidly and could produce an isolated X1 class
proton solar flare during the outlook period.
New solar region #9826 emerged in the southeast quadrant and is developing
quickly. All other solar regions are quiet and stable or slowly growing or decaying
at this moment.
SOLAR FLARES-
The period of 02/01/25 through 02/02/10 was relatively uneventful with the
largest solar flare event placed at M1.6 on 02/02/10/1848 UTC, followed by
an M1.3 on 02/01/26/2005 UTC.
I place the likelihood of a C4 class or higher solar flare at 100%, an M5
class or higher solar flare at 70% and X1 class or higher solar flare at
20%, during the upcoming 7 day outlook period.
An earthward facing M5 or higher class solar flare will move the proton flux
above 10o (10 MeV) and initiate large scale high latitude propagation path
absorption but even smaller C4 flares are the culprit behind hour to hour
and night to night variations in signal strength on the AM broadcast band
and 160 meters, both stateside and DX. as a transfer of increased density
and RF signal absorption from the day side D layer to night side of the
ionosphere occurs through high level neutral winds.
GEOMAGNETIC INDICES-
The Kp index peaked at 5 on 02/02/02/0900 UTC and 4 on 02/01/25/2100 UTC,
tied to geoeffective positioned coronal holes.
A small coronal hole in the southern hemisphere will rotate into a
geoeffective position on February 12. A Kp index of 3 is still occurring
due to residual effects from an old coronal hole. Renewed elevation of the
Kp index above 3 to as high as 5 is possible from future coronal holes but
is down from probable during the 7 day outlook period.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding
equatorward in magnetic latitude and generally begin have a possible
negative impact on mediumwave propagation. A Kp index of 5 or higher begins
to have a negative on high frequency shortwave propagation.
If the path over which you are communicating lies along or inside one of the
auroral ovals, you will experience degraded propagation in one of several
different forms: strong signal absorption, brief periods of strong signal
enhancement, which is mainly caused by tilts in the ionosphere that allow
signals to become focused at your location or very erratic signal behavior
in the form of strong and rapid fading, etc., caused by a variety of effects
such as multipathing, anomalous and rapid variations in absorption,
non-great-circle propagation, and polarization changes.
STRATOSPHERIC WARMING-
There is currently no stratospheric warming taking place and none is
expected during the 7 day outlook period. However if Arctic air
unexpectedly goes on the move again in coming days across the north pole
from Siberian Russia to North America during the period, some increased D
layer absorption of signals caused by the stratospheric warming will
occur. Sporadic E (Es) propagation is also possible.
As the stratosphere lies below the ionosphere, which is at mesosphere and
thermosphere height, you might not normally expect to see stratospheric
warming effect the AM broadcast band and 160 meter propagation in any way
BUT mediumwave frequency signals do refract off of temperature inversions
and moisture discontinuities and temperature and moisture inversions are
involved with stratospheric warming. So it's possible that a mediumwave
signal could do any number of things when refracting off of a
temperature inversion, at any height.
Just as the E layer is the main refraction medium for medium wave signal
propagation within approximately 3100 miles, so is Sporadic E (Es). Like
stratospheric level warming and tropospheric level temperature and moisture
discontinuities, Sporadic E can depending on the circumstances absorb, block
and refract medium wave RF signals in an unpredictable manner.
OUTLOOK-
The bottom line for the next 7 days? Probably a continuation of the best
overall band conditions for propagation of medium wave signals so far this
season.
To start out expect good domestic propagation on the AM broadcast band and
good propagation on 160 meters out to approximately 3000 miles. High
latitude (TA) Trans Atlantic and (TP) Trans Pacific propagation will be fair
on the AM broadcast band and good on 160 meters.
High latitude (TA) Trans Atlantic and (TP) Trans Pacific propagation
conditions should then improve to good on the AM broadcast band and very
good on 160 meters, barring any sudden elevated proton event from an Earth
facing or diffuse far side of Sun solar flare or newly developed coronal
hole.
Most stateside AM broadcast band frequencies will contain co-channel North
and Central/South American stations, with northern latitude stations
dominating at times.
There will also be some occasional lightning induced QRN across the northern
hemisphere, with an endless series of winter time approaching cold fronts
and surface extra-tropical low pressure systems.
-----
Notice, as of January 29, 2002 my KN4LF 7 Day Medium Wave Radio Propagation Outlook has been temporarily discontinued due to personal illness. It will resume shortly.
Back To The Top
KN4LF Medium Wave Radio Propagation Outlook
#2002-3 Published 11:00 PM EST 02/01/21 For 02/01/22-02/01/28
Note! Due to requests from our fellow radio brethren in the international
radio community I have adopted the date format of yy/mm/dd.
This outlook covers the upcoming CQ WW 160 Meter CW Contest which begins
02/01/25 through 02/01/27.
PREVIOUS FORECAST VERIFICATION-
Within outlook #2002-2 we discussed how solar region #'s 9773, 9775 and
9778 contained twisted delta class magnetic fields and were our best bet for
large M5 class or higher proton solar flares in coming days. Well the
magnetic fields collapsed shortly thereafter and my forecast of an M5 class
or higher solar flare at 90% and X1 class or higher solar flare at 60%
during the upcoming 7 day outlook period did not verify.
I forecasted the solar flux to return to a peak above 250 (typo said 270)
but with the collapse of the magnetic structures of the above mentioned
sunspot groups, it only reached 241 but it was still high enough for some
lesser F2 openings?! on "magic band" 6 meters.
My forecast of an M 1-4 class solar flare at 100% did verify, as well as our
forecast of a Kp above 4.
We also forecasted High latitude (TA) Trans Atlantic and (TP) Trans Pacific
propagation to be poor on the AM broadcast band and fair on 160 meters.
improving to fair on the AM broadcast band and good on 160 meters, barring
any sudden proton event. This forecast did verify, with good to very good TA
and TP openings centered around UTC 17-18th. The opening to Florida on UTC
the 17th was the best so far this season. Unfortunately though a Kp index
above 3, tied to a coronal hole stream and short lived proton flux stream
above 10 MeV (10o), tied to a diffuse arriving proton ejection from an
unidentified sunspot group on the far side of the sun during the period UTC
18-19th, pretty much ended the good propagation.
As I've said on my "KN4LF Mediumwave Radio Propagation Theory Notes" sub
website, "The best way to look at medium wave frequencies as far as
propagation issues, is to accept the fact that the majority of the time
propagation is poor, especially past approximately 1050 miles, with
occasional short lived good periods as far as 3100 miles." Why? small upward
changes in night time D layer absorption ability, tied to proton streams
from C3 or higher solar flares, has a profound negative effect on medium
wave signal refraction.
PROTON FLUX-
Per our previous outlook, a short duration >10 MeV (10+1) proton event
began on UTC 02/01/18 and ended UTC 02/01/19. More hard to predict short
lived proton flux streams above 10 MeV (10o), tied to a diffuse arriving
proton ejections from an unidentified sunspot group are possible.
A proton flux level above 10 MeV (10+1) creates elevated D absorption on
medium wave frequencies.
SOLAR FLUX-
Today's solar flux level is 225, after bottoming out at 188 on the 7th, the
first time below 200 since 02/08/07. A daily solar flux peak as high as 250
is possible in intervening days, which would be a boon to 6 meters ops.
looking for F2 propagation openings.
High solar flux values are generally considered to be detrimental to
propagation of medium wave signals both domestic and TA/TP, as more
absorption can be present via the transmitted signals two trips through the
D layer. Most long haul medium wave DX signals in excess of 3000 miles is
via the E/F layer ducting and/or E valley propagation modes. Therefore high
solar flux values can aid in long haul medium wave propagation paths in
excess of 3000 miles, as a high solar flux value ensures a strong E and F
layer duct mechanism. However high solar activity in the form of increase
ionization created by ultraviolet and x-ray radiation can fill in the E
Valley region and interfere with the E/F layer ducting mechanism. In a sense
the E/F layer duct is closed and the transmitted RF signal only propagates
between the E layer and land/ocean surface, with a higher angle and more
loss.
SUNSPOT REGIONS-
No solar regions currently contain twisted delta class magnetic fields which
would harbor potential for huge X1 class proton solar flares and our best
bet for smaller but still significant M5 class or higher proton solar flares
in coming days will be with solar region #'so 9785, 9788 and 9791.
All other solar regions are quiet and stable or slowly growing or decaying
at this moment.
SOLAR FLARES-
I place the likelihood of a C4 class or higher solar flare at 100%, an M5
class or higher solar flare at 50% and X1 class or higher solar flare at
10%, during the upcoming 7 day outlook period.
An earthward facing M5 or higher class solar flare will move the proton flux
above 10o (10 MeV) and initiate large scale high latitude propagation path
absorption but even smaller C4 flares are the culprit behind hour to hour
and night to night variations in signal strength on the AM broadcast band
and 160 meters, both stateside and DX. as a transfer of increased density
and RF signal absorption from the day side D layer to night side of the
ionosphere occurs through high level neutral winds.
GEOMAGNETIC INDICES-
Per our previous outlook, the geomagnetic Kp index was elevated to a level
of 4 at times, with a peak of 5 during the previous 7 day period, as the
Earth entered a high-speed solar wind stream flowing from a coronal hole on
the Sun. No coronal holes are currently approaching geoeffective positions
but a Kp index of 3 is still occurring due to residual effects from an old
coronal hole. Renewed elevation of the Kp index above 3 is possible from
future coronal holes but is down from probable.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding
equatorward in magnetic latitude and generally begin have a possible
negative impact on mediumwave propagation. A Kp index of 5 or higher begins
to have a negative on high frequency shortwave propagation.
If the path over which you are communicating lies along or inside one of the
auroral ovals, you will experience degraded propagation in one of several
different forms: strong signal absorption, brief periods of strong signal
enhancement, which is mainly caused by tilts in the ionosphere that allow
signals to become focused at your location or very erratic signal behavior
in the form of strong and rapid fading, etc., caused by a variety of effects
such as multipathing, anomalous and rapid variations in absorption,
non-great-circle propagation, and polarization changes.
STRATOSPHERIC WARMING-
There is currently no stratospheric warming taking place and none is
expected during the 7 day period. However with Arctic air on the move again
in coming days across the north pole from Siberian Russia to North America
during the period, some increased D layer absorption of signals caused by
the stratospheric warming will may occur by day 10. Sporadic E (Es)
propagation is also possible.
As the stratosphere lies below the ionosphere, which is at mesosphere and
thermosphere height, you might not normally expect to see stratospheric
warming effect the AM broadcast band and 160 meter propagation in any way
BUT mediumwave frequency signals do refract off of temperature inversions
and moisture discontinuities and temperature and moisture inversions are
involved with stratospheric warming. So it's possible that a mediumwave
signal could do any number of things when refracting off of a
temperature inversion, at any height.
Just as the E layer is the main refraction medium for medium wave signal
propagation within approximately 3100 miles, so is Sporadic E (Es). Like
stratospheric level warming and tropospheric level temperature and moisture
discontinuities, Sporadic E can depending on the circumstances absorb, block
and refract medium wave RF signals in an unpredictable manner.
OUTLOOK-
The bottom line for the next 7 days? Probably the best overall band
conditions for propagation of medium wave signals so far this season.
To start out expect good domestic propagation on the AM broadcast band and
good propagation on 160 meters out to approximately 3000 miles. High
latitude (TA) Trans Atlantic and (TP) Trans Pacific propagation will be fair
on the AM broadcast band and good on 160 meters.
High latitude (TA) Trans Atlantic and (TP) Trans Pacific propagation
conditions should then improve to good on the AM broadcast band and very
good on 160 meters, barring any sudden elevated proton event from an Earth
facing or diffuse far side of Sun solar flare or newly developed coronal
hole.
Most stateside AM broadcast band frequencies will contain co-channel North
and Central/South American stations, with northern latitude stations
dominating at times.
There will also be some occasional lightning induced QRN across the northern
hemisphere, with an endless series of winter time approaching cold fronts
and surface extra-tropical low pressure systems.
Back To The Top
Outlook #2002-2 Published 4:00 PM EST 01/14/02 For 01/15/02-01/21/02
PROTON FLUX-
Per our previous outlook, a short duration >10 MeV (10+2) proton event
began on 01/10/02 at approximately 2045 UTC, peaked at 91 pfu on 01/11/02 at
approximately 0530 UTC and ended on 01/13/02 at 1425 UTC. Further short duration elevated (>10 MeV) proton events are possible, tied to non Earth facing sunspot groups.
A proton flux level above 10 MeV (10+1) creates elevated D absorption on
medium wave frequencies.
SOLAR FLUX-
Also per our previous outlook, solar flux values finally fell below 200 for
the first time since 08/19/01, bottoming out at 188 on 01/07/02.
Unfortunately it has rapidly risen above 200 again, sitting at 241 on
01/13/02. A daily solar flux peak as high as 270 is possible in intervening
days, which would be a boon to 6 meters ops. looking for F2 propagation
openings.
High solar flux values are generally considered to be detrimental to
propagation of medium wave signals both domestic and TA/TP, as more
absorption can be present via the transmitted signals two trips through the
D layer. Most long haul medium wave DX signals in excess of 3000 miles is
via the E/F layer ducting and/or E valley propagation modes. Therefore high
solar flux values can aid in long haul medium wave propagation paths in
excess of 3000 miles, as a high solar flux value ensures a strong E and F
layer duct mechanism. However high solar activity in the form of increase
ionization created by ultraviolet and x-ray radiation can fill in the E
Valley region and interfere with the E/F layer ducting mechanism. In a sense
the E/F layer duct is closed and the transmitted RF signal only propagates
between the E layer and land/ocean surface, with a higher angle and more
loss.
SUNSPOT REGIONS-
Solar region #'s 9773, 9775 and
9778 contain twisted delta class magnetic fields and are our best bet for
large M5 class or higher proton solar flares in coming days. Actually these
two regions are capable of huge X1 or larger proton emitting solar flares.
All other solar regions are quiet and stable or slowly growing or decaying
at this moment.
SOLAR FLARES-
I place the likelihood of an M 1-4 class solar flare at 100%, an M5 class or
higher solar flare at 90% and X1 class or higher solar flare at 60% during
the upcoming 7 day outlook period.
A day side earthward bound M5 or higher class solar flare will move the
proton flux above 10o (10 MeV) and initiate large scale high latitude
propagation path absorption but even smaller M4 class flares and weaker,
including C7-4 flares are the culprit behind night to night variations in
signal strength on the AM broadcast band and 160 meters, both stateside and
DX. a transfer of increased density and RF signal absorption from the day
side D layer to night side of the ionosphere occurs through high level
neutral winds.
GEOMAGNETIC INDICES-
Per our previous outlook, the geomagnetic Kp index was elevated to a level
of 4 at times, with a peak of 5 during the previous 7 day period, as the
Earth entered a high-speed solar wind stream flowing from a coronal hole on
the Sun. No coronal holes are currently approaching geoeffective positions
but a renewed elevation of the Kp index above 4 is probable by 01/16/02 due
to a probable earth directed CME, ejected by an M4+ class solar flare
earlier today.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding
equatorward in magnetic latitude and generally begin have a possible
negative impact on mediumwave propagation. A Kp index of 5 or higher begins
to have a negative on high frequency shortwave propagation.
If the path over which you are communicating lies along or inside one of the
auroral ovals, you will experience degraded propagation in one of several
different forms: strong signal absorption, brief periods of strong signal
enhancement, which is mainly caused by tilts in the ionosphere that allow
signals to become focused at your location or very erratic signal behavior
in the form of strong and rapid fading, etc., caused by a variety of effects
such as multipathing, anomalous and rapid variations in absorption,
non-great-circle propagation, and polarization changes.
STRATOSPHERIC WARMING-
There is currently no stratospheric warming taking place. However with
Arctic air on the move again in coming days across the north pole from
Siberian Russia to North America during the period, some increased D layer
absorption of signals caused by the stratospheric warming will probably
occur. Sporadic E (Es) propagation is also possible.
As the stratosphere lies below the ionosphere, which is at mesosphere and
thermosphere height, you might not normally expect to see stratospheric
warming effect the AM broadcast band and 160 meter propagation in any way
BUT mediumwave frequency signals do refract off of temperature inversions
and moisture discontinuities and temperature and moisture inversions are
involved with stratospheric warming. So it's possible that a mediumwave
signal could do any number of things when refracting off of a
temperature inversion, at any height.
Just as the E layer is the main refraction medium for medium wave signal
propagation within approximately 3100 miles, so is Sporadic E (Es). Like
stratospheric level warming and tropospheric level temperature and moisture
discontinuities, Sporadic E can depending on the circumstances absorb, block
and refract medium wave RF signals in an unpredictable manner.
OUTLOOK-
The bottom line for the next 7 days?
Due to the growing mid winter anomaly expect fair to good stateside
propagation on the AM broadcast band and good on 160 meters out to
approximately 3000 miles.
High latitude (TA) Trans Atlantic and (TP) Trans Pacific propagation will
be poor on the AM broadcast band and fair on 160 meters. improving to fair
on the AM broadcast band and good on 160 meters, barring any sudden proton
event.
Most stateside AM broadcast band frequencies will contain co-channel North
and Central/South American stations, with South American stations dominating
at times.
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Outlook #2001-1A Published 2:00 PM EST 01/09/02
BANG! Per our Outlook #2002-1 Published 11:00 PM EST 01/04/02, a large size approximate M 9.5 solar flare occurred today at 1801 UTC and originated from sunspot group #9773. How did I know it occurred? I was listening to a SW broadcast station again on 13 meters, when the station abruptly weakened and nearly disappeared! This large M class solar flare is probably more earth directed then the last one and doesn't bode well for MW propagation in the next few days.
My forecast for the proton flux level and geomagnetic activity following the M 9.5 class solar flare is: elevated Kp indicies of 4-5 and also an elevated proton flux level of at least 10 +1/2. What does this mean? More D layer absorption and some high latitude propagation path blocking during the next few days, on 160 meters and even more so on the AM broadcast band.
Forgot to mention earlier that region #9773 has developed a delta-class magnetic
field that will probably pop off (scientific eh!) an earthward directed
X-class solar flare in 1-3 days.
(((Added 10:30 pm 01/10/02. Well unfortunately it looks like my forecast above verified. We have reached a Kp index of 5 and proton flux level of 10 +2! It's an interesting phenomena how delayed elevated energetic proton levels can be after an initial solar flare blast.)))
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Outlook #2002-1 Published 11:00 PM EST 01/04/02 For 01/05/02-01/11/02
The long running >10 MeV (10+3) proton event that began on 01/30/01 at approximately 0245 UTC and peaked at 108 pfu on 01/31/01 at approximately 1620 UTC, continues to slowly decay and barring any new earthward directed M5 class or higher solar flares should reach a 10o-1 level within 48 hours. A proton flux level above 10 MeV (10+1) creates increased D absorption on medium wave frequencies.
Solar flux values are still in excess of 200 with a peak of 285 on 01/27/01. Very recent values have in the low 200's and slowly falling. We may be on a trend of seeing the daily solar flux level fall below 200 for the first time since 11/28/01 when it dropped to 199. We have not seen a daily solar flux value below 150 since 08/19/01 when it dropped to 145.
High solar flux values are generally considered to be detrimental to propagation of medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signals' two trips through the D layer near sunrise and sunset. Most long haul medium wave DX signals in excess of 3000 miles is via the E/F layer ducting and/or E valley propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism. However high solar activity in the form of increased ionization created by ultravolet and x-ray radiation can fill in the E Valley region and interfere with the E/F layer ducting mechanism. In a sense the E/F layer duct is closed and the transmitted RF signal only propagates between the E layer and land/ocean surface, with a higher angle and more hops, therefore more loss.
Solar region # 9767 is basically unchanged and represents the best chance for an M class or higher proton solar flare. This sunspot group was resonsible for the X3 class proton solar flare on 12/28/01. Solar region # 9773 is rotating into view at the northeast limb and is also a solar flare threat in future days. All other solar regions are quiet and stable or slowly decaying at this moment.
The geomagnetic Kp index may be elevated to a 3 at times especially before 01/08/02.
As the Kp index reaches 3 or higher, the aurora oval regions begin expanding southward in magnetic latitude and generally begin to have a possible negative impact on high latitude mediumwave propagation paths. A Kp index of 5 or higher begins to have a negative on high latitude shortwave propagation paths. If the path over which you are communicating lies along or inside one of the auroral ovals, you will experience degraded propagation in one of several different forms: strong signal absorption, brief periods of strong signal enhancement, which is mainly caused by tilts in the ionosphere that allow signals to become focused at your location or very erratic signal behavior in the form of strong and rapid fading, etc., caused by a variety of effects such as multipathing, anomalous and rapid variations in absorption, non-great-circle propagation (skewed) and polarization changes.
Some continued increased D layer absorption of signals caused by stratospheric warming will also effect the AM broadcast band and 160 meters during the outlook period. As the stratosphere lies below the ionosphere, which is at mesosphere and thermosphere height, you might not normally expect to see stratospheric warming effect the AM broadcast band and 160 meter propagation in any way BUT mediumwave frequency signals do refract off of temperature inversions and moisture discontinuities and temperature inversions are involved with stratospheric warming. So it's possible that a mediumwave signal signal could do any number of things when refracting off of a temperature inversion, at any height.
I place the likelihood of an M 1-4 class solar flare at 100%, an M5 class or higher solar flare at 70% and X1 class or higher solar flare at 30% during the upcoming 7 day outlook period.
The bottom line for the next 7 days? Good stateside propagation on the broadcast band and 160 meters out to approximately 3100 (two hops) miles, with high latitude (TA) Trans Atlantic and (TP) Trans Pacific propagation poor on the AM broadcast band and fair on 160 meters and improving to fair on the AM broadcast band and good on 160 meters, barring any sudden proton events. There will also be some occasional lightning induced QRN across North America, with a series of approaching cold fronts and surface extra-tropical low pressure systems. Most stateside AM broadcast band frequencies will contain co-channel North and Central/South American stations, with either dominating at times.
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Outlook #2001-5 Published 4:00 PM EST 12/27/01 For 12/29/01-01/04/02
What a wild month December 2001 is turning out to be. We tenatively appear to have reached a brand new peak in this present sunspot cycle, with the highest monthly solar flux average, highest monthly sunspot number average, highest daily sunspot number and third highest daily solar flux number occuring in this month.
Sunspot region #9742 has a magnetic delta structure at the east edge of the southern leading spot group and is capable of producing another major M5 class or higher proton solar flare.
Sunspot region #9751 has developed fairly quickly and has two magnetic delta structures and is capable of a major M5 class or higher proton solar flare.
Sunspot region #9748 is mostly unchanged and can produce a minor M class solar flare.
Sunspot region #9754 is mostly unchanged and can produce a minor M class flare.
Sunspot region #'s 9743 and 9745 are quiet and stable. Sunspot region #9747 decayed slowly and quietly. Sunspot region #9752 once again decayed into a spotless plage. Sunspot region #9753 developed slowly and quietly. Sunspot region #9755 is quiet and stable.
New sunspot region #9756 has rotated into view at the southeast limb. New sunspot region #9757 has rotated into view at the southeast quadrant near the central meridian.
New sunspot region #'s 9758, 9759 and 9760 have emerged in the northeast quadrant. New sunspot region #9761 has rotated into view at the northeast limb. Sunspot region #'s 9758 and 9759 are all currently spotless.
As mentioned previously in outlook #4A, sunspot region #9742 produced a major proton solar flare. This flare was a long duration M7.1/1B proton event with associated strong type II and IV sweeps peaking at 05:35 UTC. The above 10 MeV proton event peaked at above 700 pfu. A partial halo coronal mass ejection was associated with the flare, it is uncertain if the fast CME is geoeffective. If it is, then the magnetosphere could receive an impact on December 28 or 29 causing unsettled to minor geomagnetic storming and high latitude medium wave propagation path absorption.
I place the likelihood of an M 1-4 class solar flare at 100%, an M5 class or higher solar flare at 80% and X1 class or higher solar flare at 30% during the upcoming 7 day outlook period.
The current proton event will slowly trail off form it's 10+3 peak back to 10o (10MeV) or less during the next several days.
The bottom line for the next 7 days? Fairly decent stateside propagation bit with high latitude (TA) Trans Atlantic and (TP) Trans Pacific propagation on the broadcast band nonexistent to poor and on 160 meters poor to fair with skewed paths. There will also be some occasional lightning induced QRN across North America also, with a series of approaching cold fronts and surface extra-tropical low pressure systems. Most stateside AM broadcast band frequencies will contain co-channel North and Central/South American stations, with either dominating at times. Remember though, a C4 or higher class solar flare can create sudden negative variations in night time D layer propagation absorption and an M 5 class solar flare or stronger and conditions turn very auroral real quick.
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Outlook #2001-4A Published 11:00 AM EST 12/26/01
Per our Outlook #2001-4 Published 8:00 PM EST 12/20/01, the approximate 9 day period with a low background X-Ray flux level in the C range, including virtually no solar flares above the C3 level and a proton flux level of 10o-1 (under 10 MeV) has come to an end.
Sunspot region #9742 erupted at approximately 0535 UTC today hurling an M7 class solar flare into space and creating a temporary sun facing moderate radio black out. The proton flux level has also increased to 10+3 (S3 solar radiation storm). It remains to be seen just how earth directed the Coronal Mass Ejection (CME) will be.
Solar flares at M5 level and above, as well as a proton flux level of above 10o can impact medium wave frequencies through increased RF signal absorption, starting at the bottom of the broadcast band and then working up in frequency to 160 meters, due to increased D layer ionization. Earth directed CME's will elevate the A and K geomagnetic indices while expanding the southward movement of the Aurora Oval, creating high latitude path blocking and absorption. It will take the current CME approximately 2 days to reach earth.
The bottom line? TA and TP propagation on the AM broadcast band will be continue dismal, with "some" degraded high latitude path absorption on 160 meters, especially near sunrise and sunset. However it will also be a good time to look for skewed propagation paths. The better equipped amateur stations such as W8JI will notice the least amount of negative effect on high latitude propagation paths. Also sunspot group #9742 is still capable of producing a devastating X class level solar flare.
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Outlook #2001-4 Published 8:00 PM EST 12/20/01 For 12/22/01-12/28/01
Our period of fairly good high latitude propagation path conditions on the AM broadcast band and 160 meters during the past week has been due to approximately 7 days with a low
background X-Ray flux level in the C range, including virtually no solar flares above the C3 level and a proton flux level of 10o-1 (under 10 MeV) for 7 plus days.
The fly in the ointment preventing really good propagation conditions? continued high solar flux levels above 200. The Kp index has repeatedly been at a 3-4 level during the period, demonstrating once again a lack of consistent correlation with medium wave propagation conditions.
Unfortunately though sunspot group #9742 is growing rapidly and already capable of M5 class or higher solar flares and soon will be capable of X1 or higher solar flares. High latitude propagation paths degrade dramatically with earth directed solar flares M5 and above. So unfortunately we are close to very poor high latitude path propagation again, auroral conditions!
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Outlook #2001-3A Published 10:00 AM EST 12/18/01
As ionosphere expert Dr. Robert Brown NM7M noted on the 160 meter Topband Reflector yesterday we are seeing less geomagnetic activity recently tied to the approaching winter solstice. The effects of the solar wind on the magnetosphere decrease as we approach the solstices. Why? basically it's the orientation of Earth's magnetic field with respect to the interplanetary magnetic field within the solar wind. When solar material and shock waves reach Earth their effects may be enhanced or dampened depending on the angle at which they arrive.
Most sunspot groups appear stable and quiet except for newly arrived #9742 which is growing and poses the best threat for a large solar flare in future days.
As 160 meter Amateur Radio Operators and AM Broadcast Band DX'ers have noticed in the past few days, some TA and TP DX has finally been showing up again. Why? No coincidence, as the proton flux level has been at 10o to-1 AND the background X-ray flux has been below C3. See two links below.
Click For X-Ray Flux For 12/15-16/01
Click For X-Ray Flux For 12/16-18/01
My forecast for proton flux level and geomagnetic activity following the X 6.2 class solar flare was elevated K indicies of 3-4 and also an elevated proton flux level of at least 10 +1/2, beginning on Saturday 12/15/01 and lasting through the weekend.
The actual result was an elevated K index of 3-4 and an elevated proton flux level of slightly above 10o, beginning on Saturday 12/15/01.
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Outlook #2001-3 Published 4:00 PM EST 12/14/01 For 12/15/01-12/21/01
Sunspot region 9727 is basically unchanged with a magnetic delta structure and remains capable of producing an X class flare but fortunately it will rotate over the western limb on Saturday 12/15/01. Sunspot region 9733 has changed a lot in appearance during the past 48 hours, particularly after the major X 6.2 solar flare. The magnetic delta structure has disappeared. It currently carries a magnetic beta gamma structure and is capable of an M5 class flare.
New sunspot groups are emerging in several places and further development is likely. New sunspot region 9739 emerged in the southern hemisphere over the central meridian and appears to be slowly developing, with a magnetic beta signature. New region 9740 emerged near the southeast limb, with a magnetic alpha signature. New region 9741 rotated into view at the northeast limb, with a magnetic alpha signature.
The proton flux level has been below 10o (10 MeV) to as low as 10-1 for approximately 2 days now and this should lead to some good domestic propagation within approximately 1100 miles and at times out to 3000 miles. However solar flux values continue in the 200-225 range and this will lead to some added absorption of signals not normally seen at the low part of the approximate 11 year sun spot cycle.
The X 6.2 level solar flare event on 12/13/01, ejected a coronal mass ejection (CME) that was not completely Earth directed but never the less I do expect an elevated K index of 3-4 and an elevated proton flux level of at least 10 +1/2 beginning on Saturday 12/15/01 and lasting through the weekend. Unlike HF frequencies small changes in D layer absorption has a big impact on the medium wave band, possibly including C class solar flares.
I place the likelihood of an M 1-4 class solar flare at 100%, an M5 class or higher solar flare at 70% and X1 class or higher solar flare at 40% during the upcoming 7 day outlook period.
The bottom line for the next 7 days? Fairly decent stateside propagation, with high latitude (TA) Trans Atlantic and (TP) Trans Pacific propagation on the broadcast band and 160 meters poor to marginal, with occasional openings. There will also be some occasional lightning induced QRN across North America also, with a series of approaching cold fronts and surface extra-tropical low pressure systems. Most stateside AM broadcast band frequencies will contain co-channel North and Central/South American stations, with either dominating at times. Remember though, an M 5 class solar flare or stronger and conditions turn auroral real quick.
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Outlook #2001-2C Published 10:00 AM 12/14/01
It appears that the X 2.8 class solar flare eruption on 12/11/01 has had a minimal impact on our ionosphere, as it was not completely Earth directed, on so to speak. We did have a brief period with the Boulder K index moving into the 4-5 range whci is active to minor storm and the proton flux also briefly was elevated past 10o (10 MeV).
Yesterday's solar flare event reached an X 6.2 level, VERY BIG but once again the CME was not completely Earth directed but never the less I do expect elevated K indicies above 5 and also elevated proton flux levels of at least 10 +1 to 2 beginning on Saturday. Unlike HF frequencies small changes in D layer absorption has a big impact on the medium wave band.
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Outlook #2001-2B Published 9:40 AM 12/13/01
BANG AGAIN!!! At 1425 UTC a large approximate X 6.2 Solar flare occurred and originated from sunspot groupf #9737. How did I know it occurred? I was listening to a SW broadcast station on 13 meters, when the station abruptly disappeared! This X class flare is probably more earth directed then the last one and doesn't bode well for MW propagation in the next few days.
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Outlook #2001-2A Published 3:00 PM EST 12/11/01
BANG!!! Per our 7 day outlook, twisted magnetic fields in association with sunspot group #9733 erupted today at 0805 UTC. The explosion created an X 2.8-class solar flare which has initiated a strong radio blackout across Europe and much of Asia. As the proton flux has only inched up to near 10o (10 MeV) as of 2000 UTC, it's unclear at this time just how much of an impact the CME will have. Stay tuned, though as high latitude propagation path absorption should increase in some form tonight and during the next 24 hours, peaking by Friday 12/14/01.
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Outlook #2001-2 Published 4:00 PM EST 12/06/01 For 12/08/01-12/14/01
The proton flux level has been below 10o (10 MeV) to as low as 10-1 for approximately 5 days and this should lead to some good domestic, high latitude (TA) Trans Atlantic and (TP) Trans Pacific propagation for the ARRL 160 meter contest and also on the broadcast band. Also as an added bonus, lightning induced QRN should be at reasonably low levels across North America, though the deep south could experience periods of elevated QRN with an approaching cold front.
Alas though, the solar flux is above 247 and this will lead to some added absorption of signals not normally seen at the low part of the approximate 11 year sun spot cycle.
Sunspot 9727 has developed a delta-class magnetic field and poses a threat for an X-class solar flare or two. Meanwhile sun spots 9715 and 9718 have beta-gamma magnetic fields that contain energy for M-class flares. An earthward bound M7 or higher class solar flare will initiate high latitude propagation path absorption.
I place the likelihood of an M 5 class or higher solar flare at 80% and and X1 class or higher solar flare at 40% during the 7 day period.
The bottom line for the next 7 days? No substantial solar flares and high latitude path medium wave conditions continue to improve. However we cannot expect really good openings with the present high solar flux levels. M7 class solar flare or stronger and conditions are back to where they have been most of this DX season so far, lousy.
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Outlook #2001-1A Published 4:00 PM EST 12/03/01
The proton flux level has been below 10o (10 MeV) to as low as 10-1 for approximately 48 hours and this should lead to some of the best domestic, (TA) Trans Atlantic and (TP) Trans Pacific propagation on the broadcast band and 160 meters in quite some time tonight. Alas though, the solar flux is above 230 and this will lead to some added absorption of signals, especially below approximately 1100 kc.
Sunspot regions 9715, 9717 and 9718 have beta-gamma magnetic fields that contain energy for M 5 class flares or higher. The peak daily solar flux so far this 7 day forecast period has been 249.
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Outlook #2001-1 Published 12:00 PM EST 12/01/01, For 12/01/01-12/07/01
Solar activity is high. The approximate 28 day cyclical solar flux minimum was 170 on 11/25/01. Today it's 221 and rising. The past three solar flux peaks were 271 on 11/09/01, 263 on 10/19/01 and 285 on 09/28/01. The next 28 day cyclical solar flux peak may exceed 250 or even reach 270.
High solar flux values are generally considered to be detrimental to medium wave signals both domestic and TA/TP, as more absorption can be present via the transmitted signals two trips through the D layer, near sunrise and sunset. However even with a solar flux in excess of 200 I have personally been hearing WSM 650 kc Nasheville, TN. as well as skywave signals on 160 meters here in Central Florida during local high noon the past couple of days, through the D layer at it's height of ionization, so it's not a hard fast rule. Most long haul medium wave DX signals in excess of 3000 miles is via the E/F layer ducting and/or E valley propagation modes. Therefore high solar flux values can aid in long haul medium wave propagation paths in excess of 3000 miles, as a high solar flux value ensures a strong E and F layer duct mechanism.
Sunspot regions 9715, 9718 and 9720 have the potential for producing M-class flares, via CME's (coronal mass ejections). M5 class solar flares and above have the energy to produce visible aurora and elevated proton flux levels in excess of 10 MeV, a level capable of absorbing high latitude medium wave signals and creating what we normally call auroral conditions, when signals from a southerly direction are co-channel with or dominant over northerly direction signals.
Region 9715 has good potential to produce an X-class solar flare or two. X class solar flares have the ability to create visible aurora south of 30 degrees north latitude and north of 30 degrees south latitude, polar radio blackouts, polar cap absorption, high and mid latitude absorption via D layer overionization and ionospheric storms. X class solar flares can produce a lingering negative effect on high latitude medium wave propagation paths, long after all elevated events are over and the A and K indices return to normal. I don't pay much attention to the A and K indices as they don't correlate very well with medium wave propagation conditions. The key is the proton flux level above 10o (10 MeV). The higher the proton mev level the higher the frequency absorbed.
I place the likelihood of an M 5 class or higher solar flare at 90% and and X1 class or higher solar flare at 50% during the 7 day period.
The bottom line for the next 7 days? No substantial solar flares and high latitude path medium wave conditions continue to improve. M7 class solar flare or stronger and conditions are back to where they have been all season so far, lousy!
As the proton flux drops below 10o (10 MeV) expect improved domestic east west propagation and improved TA and TP propagation especially on higher frequencies. However there can still be some co-channel signals from the Caribbean, Central and South America, especially on the lower frequencies.
If the proton flux dips well below 10o (10 MeV) for a couple of days and it's doubtful at the moment, expect much improved TA and TP reception.
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Published 12:00 PM EST 12/01/01.
I was operating on 160 meters, as well as listening to the domestic AM broadcast band tonight. Distant signals were much louder tonight, for the
first time in a good while, especially from a northerly direction. We are on
the verge of normal MW band conditions for TA and TP DX, as the proton flux
has inched it's way down to 10o (10 MeV).
I've been watching the proton flux and the A & K indices for a long time and
can see a direct correlation between a high proton flux and poor high
latitude MW propagation paths, where as the A & K don't as readily
correlate.
Unfortunately though the large (6 earth diameters) size and growing sunspot #9715
has developed a beta-gamma-delta magnetic twisted "delta-class" magnetic
field that harbors energy for powerful X-class eruptions. This spot is
nearing the center of the Sun, so explosions from its vicinity this week
will likely be Earth-directed.
It's been a dismal MW DX season so far with one solar flare after another
and attendant polar radio blackouts, polar cap absorption, high and mid latitude absorption and ionospheric storms.
Note! I use "RAW" public domain data from the NOAA Space Environment Center, as well as other U.S.
Government organizations, to produce my "not for profit" propagation forecast outlooks. This data is
gathered and made public by the U.S. Government using taxpayer $$$. However the forecast outlooks
that I produce from the "RAW" public domain data, is my personal intellectual property. Therefore
the propagation outlooks contained herein is copyrighted © 1988-2003 by Thomas F. Giella, KN4LF,
all rights reserved. Reproduction of information herein is allowed as long as proper credit is
given.
Space weather forecasting is still an inexact science. The discussions, forecasts and
outlooks are not official but for educational purposes only and are subject to human error
and acts of God, therefore no guarantee or warranty implied.
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