[HCDX] KN4LF Daily HF/MF Radio Propagation Outlook #2003-09
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[HCDX] KN4LF Daily HF/MF Radio Propagation Outlook #2003-09
KN4LF Daily HF/MF Radio Propagation Outlook #2003-09
http://www.kn4lf.com/kn4lf5.htm
Date Format is YY/MM/DD
Published Wednesday 03/08/30 At 1800 UTC
PAST 24 HOUR SOLAR, SPACE WEATHER AND GEOMAGNETIC INDICES-
Solar Flux Readings- 114 116 117
Sunspot Number- 132
X-Ray Solar Flares- C-1 M-0 X-0
Averaged Background X-Ray Flux- B2.8
Energetic Protons >10 MeV (10+0)- None
Coronal Hole #054 which became geo-effective on 03/08/28 will begin impacting the geo-magnetic field with minor storm conditions Kp-5 by 03/09/01.
In the past 24 hour period the Ap index has been at active levels, with a peak at 28.
In the past 24 hour period the Kp index has been at minor storm levels, with a peak at 5. The short lived minor storm level was due to the lopsided partially geo-effective Coronal Mass Ejection that was hurled into space on 03/08/25.
Here are some general guidelines concerning correlation of propagation indices to actual expected HF/MF propagation conditions.
1.) Dropping indices numbers are better, except for solar flux on HF.
2.) For medium frequencies a solar flux under 150, under 100 better, 70 is best for E layer multi hop. Keep in mind though that the 10.7 cm (2800 mhz) solar flux index is not a "reliable" gauge of ionization in our atmosphere, as the energy of photons at this frequency is to low on the order of one million times.
2a.) For high frequencies a solar flux of 100 is okay, 150 better, above 200 best for F 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 C1 for several days consecutively for 160/120 meters and less then B9 for MF broadcast band.
8.) No current STRATWARM alert.
9.) IMF Bz with a (+) positive sign, indicates a lesser chance of high latitude path auroral absorption/unpredictable refraction or scattering of MF RF signals, when the Kp is above 3.
PROPAGATION LESSON-
MF Propagation Overview Continued -
E.) After much personal observational research over a 30 year period, I've come to the conclusion that high and mid latitude TA and TP propagation paths tend to open up only after a significant period of time passes with an energetic proton event of no greater then (10+0) on 160 meters and no greater then (10-1) on the medium frequency broadcast band. Openings also occur when the average solar background X-ray level falls back to or below C1 for 160 meters and B9 for the AM broadcast band.
F.) Remember though that there are daily extremes of the Background X-ray flux level. So even though the daily average might have been good at say B2.2, the daily "extreme" maximum could have been C1.5, which would have been bad and have cause a short period of increased D layer absorption.
G.) Though high latitude propagation paths on the day light side of the Earth are primarily affected, night time high latitude paths can also be impacted by higher intensity energetic proton events. This fact is still stubbornly opposed by some otherwise very knowledgeable space weather physicists hung up on high latitude threshold Riometer data tied to Polar Cap Absorption (PCA).
H.) Another wrench in the gears preventing consistent good propagation on medium frequencies is related to Sporadic-D (Ds) absorption. Sporadic-D (Ds) occurrences have an inter-relationship with brief but intense Sun based and Galactic Cosmic Rays, huge positive cloud to ground lightning strokes and interrelated Sprites and Elves. Very large bursts of Gamma Rays have also been observed to occur in conjunction with Sprites.
I.) Also there is another unavoidable problem, Magneto Ionic Power Coupling. Antenna polarization plays a large role in the success of a long haul DX contact. As a medium frequency RF signal traverses our planets magnetic lines of force in a perpendicular manner on high and mid latitude paths say between W3 land and SM, higher angle horizontally polarized signals are more readily absorbed then lower angle vertically polarized signals. On other propagation paths on the globe opposite results can be found, i.e. horizontally polarized signals suffer less absorption on a propagation path between VK6 and W4. Magneto Ionic Power Coupling expert Bob Brown NM7M has a good educational thread on this propagation bugaboo on the May 2002 Topband Reflector.
J.) Meteorological effects such as troposphere originating Internal Buoyancy/Gravity Waves (IBGW), stratospheric level Quasi-Biennial Oscillations (QBO) and stratospheric warming (See definition #16 on Stratospheric Warming) have a negative effect on MF RF signals in the form of small to medium increased absorption variations of MF RF signals via the D layer. Also temperature and moisture discontinuities (frontal inversions) can refract/scatter MF radio signals in unpredictable ways, most notably on high transmitted RF power levels.
K.) The Quasi-Biennial Oscillation (QBO) is a wind shift in the equatorial stratosphere, an oscillation from easterly to westerly and back on the time scale of approximately two years (26 months) and is a source of internal gravity waves (IGW) which create absorptive perturbations in the D and E layers and even possibly the F-1&2 layers.
L.) The HAARP Ionospheric program, Thunderstorms, lightning (especially positive cloud to ground strokes), sprites, tornadoes, hurricanes and even man made activities such as rocket launches including the space shuttle, are all sources of (IBGW's). Many times I've heard ham's lament that propagation was going to go to crap due to another space shuttle launch, in a sense they are correct. Much more research is needed on MF and LF radio wave propagation.
PROPAGATION OUTLOOK-
We should continue to see periods of unsettled Kp-3 to active Kp-4 geomagnetic conditions, with some minor storm Kp-5 to moderate storm Kp-6 conditions probable beginning on 03/09/01.
GLOBAL HF 3000-30000 KC PROPAGATION CONDITIONS EXPECTED-
Low Latitude- Good
Mid Latitude- Good
High Latitude- Good Becoming Fair To Poor
GLOBAL MF 300-3000 KC PROPAGATION CONDITIONS EXPECTED-
Expect good but becoming fair "Northern Hemisphere" domestic propagation conditions on east-west paths.
Expect fair then becoming poor domestic conditions on north "TO" south paths in the "Northern Hemisphere" out to approximately 1100 miles.
Expect fair then becoming good domestic conditions on south "TO" north paths in the "Northern Hemisphere" out to approximately 1100 miles.
Expect good but then becoming fair "Southern Hemisphere" domestic propagation conditions on east-west paths.
Expect fair then becoming good domestic conditions on north "TO" south paths in the "Southern Hemisphere" out to approximately 1100 miles+
Expect fair then becoming poor conditions on south "TO" north paths in the "Southern Hemisphere" out to approximately 1100 miles.
"High latitude" Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3200 miles should be fair then becoming poor.
"High latitude" Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3200 miles should be fair then becoming poor.
"Mid latitude" Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3200 miles should be good then becoming fair.
"Mid latitude" Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific and cross equatorial propagation conditions in excess of approximately 3200 miles should be good then becoming fair.
"Low latitude" Northern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific propagation conditions in excess of approximately 3200 miles should be good.
"Low latitude" Southern Hemisphere (TA) Trans Atlantic, (TI) Trans Indian, (TP) Trans Pacific propagation conditions in excess of approximately 3200 miles should be good.
Propagation Forecast Scales-
Excellent- +1 db Over S9 Or better
Good- S7-9
Fair- S4-6
Poor- S1-3
NOISE (QRN) OUTLOOK-
GLOBAL SATELLITE DERIVED LIGHTNING STRIKE DATA
(See Where Your QRN Is Coming From)
http://aviationweather.gov/gcd/graf/expconus.gif
http://aviationweather.gov/gcd/graf/exptropical.gif
During the 24 hour outlook period there will be "high" lightning induced QRN levels in low latitude areas of the Northern Hemisphere due to the proximity of the Inter-Tropical Convergence Zone (ITCZ) and tropical cyclones.
Northern hemisphere mid latitude regions can expect "moderate to high" lightning induced QRN tied to summer season thunderstorms, cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems and tropical cyclones.
Northern hemisphere high latitude regions can expect "moderate" lightning induced QRN tied to summer season thunderstorms, cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.
During the outlook period there will be "high" lightning induced QRN levels in low latitude areas of the Southern Hemisphere due to the proximity of the Inter Tropical Convergence Zone (ITCZ) and tropical cyclones.
Southern hemisphere mid latitude regions can expect "moderate" lightning induced QRN, tied to winter season thunderstorms cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.
Southern hemisphere high latitude regions can expect "low" lightning induced QRN tied to winter season thunderstorms, cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems.
Space Weather Scales-
Kp Indices-
G5 = Extreme Storm - Kp = 9
G4 = Severe Storm - Kp = 8
G3 = Strong Storm - Kp = 7
G2 = Moderate Storm - Kp = 6
G1 = Minor Storm - Kp = 5
Active - Kp = 4
Unsettled - Kp = 3
Ap Indices-
Ap 100-400 Severe Storm
Ap 50-99 Major Storm
Ap 30-49 Minor Storm
Ap 16-29 Active
Ap 0-7 Quiet
Correlation Of Kp To Ap Indices-
K- 0= A- 0
K- 1= A- 3
K- 2= A- 7
K- 3= A- 15
K- 4= A- 27
K- 5= A- 48
K- 6= A- 80
K- 7= A- 140
K- 8= A- 240
K- 9= A- 400
73 & GUD DX,
Thomas F. Giella, KN4LF
Plant City, FL, USA
KN4LF Daily Solar Space Weather & Geomagnetic Data Archive &
Daily HF/MF Radio Propagation Outlook http://www.kn4lf.com/kn4lf5.htm
KN4LF HF/MF Radio Propagation Theory Notes
http://www.kn4lf.com/kn4lf8.htm
KN4LF 160 Meter Amateur Radio Resources & More
http://www.kn4lf.com/kn4lf.htm
Florida Space & Atmospheric Weather Institute
http://www.kn4lf.com/fsawi.htm
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