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[HCDX] KN4LF Daily LF/MF/HF Radio Propagation Outlook #2005-004
KN4LF Daily LF/MF/HF Radio Propagation Outlook #2005-004
http://www.kn4lf.com/kn4lf6.htm
Date Format is MM/DD/YYYY
Published Thursday 01/20/2005 At 2200 UTC Valid 01/21-27/2005
DISCUSSION-
To say it's been a very active week for solar, space and geomagnetic weather is an understatement! My forecast for a strong (Kp-7) geomagnetic storming verified. Also I forecasted the daily solar flux to reach 150 and it reached 149. Overall the forecast for 01/14-20/2005 was one of my best since I started producing the outlooks again.
Now the forecast for the week of 01/20-21/2005 is much tougher. Prolific solar flare producing sunspot group #10720 will be setting around the western limb of the Sun in a couple of days but continues to produce large solar flares at the time of this writing. We currently have two new coronal mass ejections enroute Earth but both are probably only partially (Earth facing) geoeffective. The newest one released from the X7.1 solar flare this morning though only partially geoeffective, is a very large impulse and very hard to judge as far as it's potential impact on our magnetic field in one to two days. I'm hedging that it will produce no more than moderate geomagnetic storming.
We also have recurrent sunspot group #10715 returning in four days, which last month was a prolific producer of solar flares.
SOLAR, SPACE WEATHER AND GEOMAGNETIC CONDITIONS EXPECTED-
During the period quiet to active (Kp 0-4) geomagnetic conditions "WILL OCCUR".
During the period minor (Kp-5) geomagnetic storming is "WILL OCCUR".
During the period moderate (Kp-6) geomagnetic storming is "PROBABLE".
During the period strong (Kp-7) geomagnetic storming is "POSSIBLE".
During the period Severe To extreme (Kp-8-9) geomagnetic storming is "IMPROBABLE".
The chance of polar cap absorption on high latitude propagation paths due to excessive energetic protons >10 Mev (10+0) is "HIGH".
The chance of daylight side SID radio blackouts from solar flares is "HIGH".
The chance of a geoeffective (Earth facing) Coronal Mass Ejection (CME) is "HIGH".
The chance of a geoeffective (Earth facing) Coronal Hole is "HIGH".
Daily solar flux levels should range between 135-85.
Sunspot group #10720 located at N14W56 currently contains a twisted beta-gamma-delta magnetic signature capable of producing M & X class solar flares.
The chance of a small C class solar flare is "HIGH".
The chance of a large M class solar flare is "HIGH".
The chance of a huge X class solar flare is "HIGH".
GLOBAL LF 30-300 KC PROPAGATION CONDITIONS EXPECTED-
Daytime- Fair to poor.
Nighttime- Poor for ham signals, fair for broadcast signals.
GLOBAL HF 3000-30000 KC PROPAGATION CONDITIONS EXPECTED-
Low Latitude- Fair to good.
Mid Latitude- Poor to good.
High Latitude- Poor to fair.
GLOBAL MF 300-3000 KC PROPAGATION CONDITIONS EXPECTED WITH AN EMPHASIS ON THE MF AM BROADCAST BAND, 160 METERS AND 120 METERS-
-Expect poor to fair "Northern Hemisphere" domestic propagation conditions on east-west paths out to approximately 1100 miles.
*Expect poor "Northern Hemisphere" domestic conditions on north "TO" south paths out to approximately 1100 miles.
+Expect good "Northern Hemisphere" domestic conditions on south "TO" north paths out to approximately 1100 miles.
-Expect poor "Southern Hemisphere" domestic propagation conditions on east-west paths out to approximately 1100 miles.
+Expect good "Southern Hemisphere" domestic conditions on north "TO" south paths out to approximately 1100 miles.
*Expect poor conditions on south "TO" north paths in the "Southern Hemisphere" out to approximately 1100 miles.
Equatorial region domestic propagation conditions out to approximately 1100 miles should be good to fair.
"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 to 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 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 fair to good.
"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 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 fair to good.
Equatorial region to Northern Hemisphere "mid latitude" propagation conditions in excess of approximately 3200 miles should be good.
Equatorial region to Southern Hemisphere "mid latitude" propagation conditions in excess of 3200 miles should be fair.
Equatorial region to Northern Hemisphere "high latitude" propagation conditions in excess of approximately 3200 miles should be fair to poor.
Equatorial region to Southern Hemisphere "high latitude" propagation conditions in excess of 3200 miles should be poor.
Propagation Forecast Scales-
Excellent- +1 db Over S9 Or better
Good- S7-9
Fair- S4-6
Poor- S1-3
GLOBAL NOISE (QRN) OUTLOOK-
U.S. LIGHTNING STRIKE DATA
(See Where Your QRN Is Coming From)
Sorry but global views of near real time lightning strikes are no longer available.
http://www.lightningstorm.com/tux/jsp/gpg/lex1/mapdisplay_free.jsp
During the 7 day outlook period there will be "HIGH" lightning induced QRN levels in low latitude areas of the Northern Hemisphere tied to winter season thunderstorms, cold/warm/occluded fronts, associated extra-tropical cold core low pressure systems and El Nino.
Northern hemisphere mid latitude regions can expect "HIGH TO MODERATE" lightning induced QRN tied to winter season thunderstorms, cold/warm/occluded fronts, associated extra-tropical cold core low pressure systems and El Nino.
Northern hemisphere high latitude regions can expect "MODERATE TO LOW" lightning induced QRN tied to winter season thunderstorms, cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems and El Nino.
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 "HIGH" lightning induced QRN, tied to summer season thunderstorms and tropical cyclones.
Southern 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.
END OF OUTLOOK
SOLAR, SPACE WEATHER AND GEOMAGNETIC INDICES FOR THE PERIOD 01/14-20/2005
Sunspot Groups-
Sunspot group #10720 located at N14W56 currently contains a twisted magnetic signature capable of producing M & X class solar flares.
Solar Flux Readings- 128-149
SEC Sunspot Number- 65-109
Solar Wind Speed- 443-1004
X-Ray Solar Flares- C-76 M-21 X-5
Averaged Daily Background X-Ray Flux- B6.8-C1.6
Dst Index- -5 to -125
Elevated Energetic Protons >10 MeV (10+o)- 2, Max 5040 pfu
Geoeffective (Earth Facing) Coronal Mass Ejections- 4
Partially geoeffective (Earth Facing) Coronal Mass Ejections-2
Geoeffective Coronal Holes- 1, CH #140 1/18/05
Strong polar cap absorption on high latitude propagation paths has occurred due to excessive energetic protons >10 Mev (10+0) occurred.
The Ap index has been at quiet to severe geomagnetic storm levels, with a range of 4 to 132.
The Kp index has been at quiet to strong geomagnetic storm levels, with a range of 1 to 7.
The Boulder K index has been at quiet to moderate geomagnetic storm levels, with a range of 1 to 6.
Here are some "general" guidelines concerning correlation of propagation indices to actual expected HF/MF propagation conditions.
1.) Dropping indices numbers are better, with the exception of solar flux and sunspot number on HF.
2.) For medium frequencies a solar flux under 150, under 100 better, 70 is best for E layer multi hop. For high frequencies over 125 is good, over 150 is better, over 200 is best.
Keep in mind though that at medium frequencies 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. However most are used to solar flux and sunspot number and it's a hard habit to break. A better indicator is the background x-ray flux. See #7.
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 AM 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 but A9 or less is best.
8.) No current STRATWARM alert.
9.) IMF Bz with a (+) 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. 10.) A -50 or better towards a positive number Dst index during the recovery time after a geomagnetic storm, as related to the Equatorial Ring Current.
TODAY'S PROPAGATION LESSON -
E Valley-F Layer Propagation Ducting Mechanism/Chordal Hop Propagation-
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 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.
You would expect a true long path QSO on 160 to be theoretically possible but improbable on most paths during any season. However a G to VK long path might be possible if the E-valley/F-layer ducting propagation mechanism or the Chordal Hop propagation mechanism is involved. A 160 meter signal can traverse a daylight path via these propagation modes if the transmitted signal enters/exits at each end of the path at or near sunrise/sunset when the D layer ionization is weak (ionospheric tilting).
The downward tilt of ionospheric layers is eastward at sunrise As a result, signals coming from the west are refracted downward at steeper angles and are therefore heard better on higher angle antennas. The opposite is true at local sunset.
A note though, the E-valley/Flayer ducting propagation mechanism does not exist only during gray line periods. Internal Buoyancy/Gravity Waves (IBGW's) are a source of the ducting mechanism and allow for occurrences of ducting along any propagation path in total darkness. Measurement of the timing of arrival of propagated MF RF signals demonstrates the existence of the ducting mechanism, versus conventional numerous E layer land/ocean surface hops.
The majority of the time medium frequency RF signals in excess of approximately 3200 miles propagate via the E-valley/F-layer propagation mechanism or via the Chordal Hop (mostly on HF) propagation mechanism. High solar flux values can aid in long haul medium frequency propagation, as high solar flux values ensure a strong F-layer half of the E-Valley/F-layer duct mechanism. Typically the majority of transmit antenna's radiation must be focused between 40-60 deg. to enter the E-Valley/F-layer duct.
If one is lucky enough to be on the receive end of a ducted medium frequency signal due to an IBGW or two, a change in the vertical and/or horizontal electron gradient will allow the RF to drop out of the duct at your QTH.
A note, high solar activity in the form of increased ionization created by ultraviolet and X-ray radiation, can fill in the E-Valley/F-layer ducting region with medium frequency absorptive ionization and interfere with the E- Valley/F-layer ducting mechanism. In a sense the E/F layer duct is shut down and the medium frequency RF signal can only propagate between the E-layer and land/ocean surface, at a higher angle and with more signal loss. This closing of the duct can be reciprocal on each end of the propagation path or one way only. (((((When closing of the duct occurs the advantage of a low angle vertical radiator is lost, with a higher takeoff angle horizontal dipole making the contact still possible, albeit maybe weaker.)))))
Medium frequency radio waves possess elliptical polarization, with the signal splitting into ordinary and extra-ordinary rays. These rays can propagate in or out of phase, mainly out of phase. The out of phase extra-ordinary ray represents a 50% power loss on the receive end of a propagation path.
For more information go to KN4LF HF/MF Frequency Radio Propagation Theory Notes at http://www.kn4lf.com/kn4lf8.htm .
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 8-15 Unsettled
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
Standard Disclaimer-
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 © 1988-2005 by Thomas F. Giella, KN4LF. Reproduction of information herein is allowed as long as proper credit is given.
Also 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.
73 & GUD DX,
Thomas F. Giella, KN4LF
Retired Space & Atmospheric Weather Forecaster
Plant City, FL, USA
Grid Square EL87WX
Lat & Long 27 58 33.6397 N 82 09 52.4052 W
kn4lf@xxxxxxxx
Propagation eGroup: http://lists.contesting.com/mailman/listinfo/propagation
KN4LF Daily Solar Space Weather & Geomagnetic Data Archive: http://www.kn4lf.com/kn4lf5.htm
KN4LF HF/MF Frequency Radio Propagation Theory Notes: http://www.kn4lf.com/kn4lf8.htm
KN4LF Amateur & SWL Radio History: http://www.kn4lf.com/index.htm
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