[HCDX] KN4LF 7 Day MF RX Prop. Outlook #2002-25

["Thomas Giella, KN4LF" <kn4lf@xxxxxxxxxxxxxxx>]

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.

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 02/09/16-02/09/22 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.

73,
Thomas Giella, KN4LF
Plant City, FL

KN4LF 160 Meter Amateur Radio Resources:
http://www.kn4lf.com

KN4LF Daily Solar Space Weather Geomagnetic Data Plus
MF Propagation Outlook:
http://www.kn4lf.com/kn4lf5.htm

FL Meteorological & Climatic Institute:
http://www.kn4lf.com/sub/fmci.htm

Giella Website Design:
http://www.thomasgiella.com



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