KN4LF Daily HF/MF Radio Propagation Outlook #2003-20 http://www.kn4lf.com/kn4lf5.htm
Date Format is MM/DD/YY Published Tuesday 12/11/03 At 0400 UTC PAST 72 HOUR SOLAR, SPACE WEATHER AND GEOMAGNETIC INDICES- Sunspot Groups- No sunspot groups currently contain a twisted magnetic field capable of producing large M class solar flares or huge X class solar flares. Solar Flux Readings- 94 to 88. The daily solar flux reading of 88 that occurred on the 12/10/03 was the lowest since 03/98, which was on the rising side of solar cycle 23. SEC Sunspot Number- 49 to 23. X-Ray Solar Flares- C-0 M-0 X-0 X-Ray Solar flare activity continues quiet but activity will increase as sunspot group #10501 rotates around the east limb of the Sun shortly. Averaged Background X-Ray Flux- B1.2 to A8.7. Energetic Protons >10 MeV (10+o)- None. Geo-effective (Earth Facing) Coronal Mass Ejections- None. Recurrent Coronal Hole #071 became geoeffective beginning on 12/5/03. As #066 on 11/9-14/03 it produced a Kp of 6 (moderate geomagnetic storm). I expect a Kp of 5 (minor geomagnetic storming) to a Kp-6 (moderate geomagnetic storming to continue for another 72 hours. The Ap index has been at quiet to major storm levels, with a range of 7 to 69. The Kp index has been at quiet to moderate storm levels, with a range of 2 to 6. The solar wind speed has ranged between 352 and 800. Here are some "general" guidelines concerning correlation of propagation indices to actual expected HF/MF propagation conditions. 1.) Dropping indices numbers are better, except solar flux for HF. 2.) For medium frequencies a solar flux under 150, under 100 better, 70 is best for E layer multi hop. 2a.) For high frequencies a solar flux of 100 is okay, 150 better, above 200 best for F 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. 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 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 (+) 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. TODAY'S PROPAGATION LESSON #1- 1.) HF/MF Propagation Overview- a.) Medium frequencies encompass 300 to 3000 kc. The simplest way to look at medium frequencies with respect to propagation issues from a layman's point of view, is to accept the fact propagation is poor the majority of the time. (See definition #6. Electron Gyro Frequency Absorption), especially past approximately 1250 miles (one refraction off of the E-layer), with occasional short-lived good periods as far as 3200 miles. 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 path. b.) Why? D-layer absorption! At daytime the D-layer, which is at an approximate height of 30-60 miles in the mesosphere, totally absorbs medium frequency RF signals most of the time. I say most of the time because at high latitudes, during the winter season and especially at the low part of a sunspot cycle, penetration of RF signals through the weakened D-layer and then refraction via the E-layer does occur. However a fly-in-the-ointment is the fact that the D-layer does not totally disappear at night. Many books that deal with wave propagation erroneously state that the D and E-layers disappear after sunset, totally incorrect thanks to Galactic Cosmic Rays. c.) Background electromagnetic radiation in the 1 to 10 Angstrom range (Hard X-Rays) is the main source of ionization of the day time D-layer, with our Sun as the source of Cosmic Rays, also playing a role. The following paragraph was contributed by Carl Luetzelschwab K9LA. A couple years ago I was playing with Proplab Pro on a one-hop 936km path on 160m during daylight. I plotted absorption versus sunspot number. I expected a nice monotonic increase as the sunspot number increased. But the plot showed that absorption started at about 60dB at zero sunspots and was constant out to a sunspot number of about 50. Then it started climbing, reaching 100dB at a sunspot number of 150. This suggested that there was something other than hard x-rays and cosmic rays as the source of daytime D region absorption. So I dug into Davies 1990 (page 61), Hunsucker and Hargreaves (page 31), and Brekke (page 233). They all seem to point to the Lyman-alpha line of the solar spectrum at 1215 Angstroms ionizing NO as the main source of the quiet daytime D region. So in terms of my absorption versus sunspot number plot, the flat portion up to a sunspot number of 50 is probably due to the Lyman-alpha line ionizing NO. Then above a sunspot number of 50 the hard x-rays start contributing as the Sun becomes more active. d.) While I'm visiting the subject of electromagnetic radiation, our Sun emits electromagnetic radiation and matter, as a result of the nuclear fusion process. Electromagnetic radiation at wavelengths of 100 to 1000 Angstroms (Ultraviolet) ionizes the F region, radiation at 10 to 100 Angstroms (Soft X-rays), as well as Cosmic Rays ionize the E region. Galactic Cosmic Rays are the reason that the E-layer is "always" present at night time, the D-layer also. Cosmic rays are not rays at all, but particles. They are ionized atoms, atoms with missing electrons ranging from a single proton up to an iron nucleus and beyond but typically protons and alpha particles, which have 2 protons and 2 neutrons. They originate from deep space, being produced by a number of different sources, such as other stars, and more exotic objects, such as supernova, which are exploding stars and their remnants, neutron stars, black holes, and distant galaxies. Cosmic Ray particles travel very close to the speed of light, and are highly energetic. e.) Recently I saw a post on the Topband Reflector E-List, lamenting the seemingly unexplainable differences in 160 propagation on certain paths from night-to-night. A reasonable explanation? Yes, unfortunately small increases in the density of the night time D-layer over short periods of time, caused by smaller solar flares and also the general variability of the solar background X-Ray flux level, can have a profound negative impact on propagation in the form of increased absorption of high and even mid-latitude medium-frequency signal paths, both on the MF broadcast band, 160 and 120 meters. Why? It only takes 10 electron volts (ev) of energy to ionize the atmosphere and 1-10 Angstrom X-ray photons energize the atmosphere at a factor of 100. This translates into D layer absorption of medium frequency signals. The lower half of the MF broadcast is always affected first followed by the upper half of the AM broadcast band, then 160 and 120 meters. If you learn nothing else on this website, remember this simple explanation and pass the word. f.) 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. g.) 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. h.) Though high latitude paths on the day light side of the Earth are primarily effected, 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). i.) 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. j.) 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 background propagation path between VK6 and W4. Magneto Ionic Power Coupling expert Bob Brown NM7M has a good educational thread on this bugaboo on the May 2002 Topband Reflector. The thread can read in it's entirety by going to my main radio website page at http://www.kn4lf.com and clicking on the "Topband Reflector Archive" link in the left-hand column. k.) Meteorological effects such as troposphere originating Internal Buoyancy/Gravity Waves (IBGW), stratospheric level Quasi-Biennial Oscillations (QBO) and 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. l.) 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 Buoyancy/Gravity Waves (IBGW's) which create absorptive perturbations in the D and E layers and even in the F-1&2 layers. m.) 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. 72 HOUR PROPAGATION OUTLOOK- We will see continued minor storm Kp-5 to moderate storm Kp-6, with occasional active Kp-4 geomagnetic conditions through the next 72 hours, thanks to recurring Coronal Hole #071. GLOBAL LF UNDER 300 KC PROPAGATION CONDITIONS EXPECTED- Daytime- Good Nighttime- Poor GLOBAL HF 3000-30000 KC PROPAGATION CONDITIONS EXPECTED- Low Latitude- Good Mid Latitude- Good to Fair High Latitude- Fair To Poor GLOBAL MF 300-3000 KC PROPAGATION CONDITIONS EXPECTED- Expect fair to poor "Northern Hemisphere" domestic propagation conditions on east-west paths. *Expect poor domestic conditions on north "TO" south paths in the "Northern Hemisphere" out to approximately 1100 miles. +Expect good domestic conditions on south "TO" north paths in the "Northern Hemisphere" out to approximately 1100 miles. Expect fair to poor "Southern Hemisphere" domestic propagation conditions on east-west paths. +Expect good domestic conditions on north "TO" south paths in the "Southern Hemisphere" out to approximately 1100 miles. *Expect 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 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 to good. "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://www.lightningstorm.com/tux/jsp/gpg/lex1/mapdisplay_free.jsp;jsessionid=70301187101071113657379 During the 72 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" lightning induced QRN tied to winter season thunderstorms, cold/warm/occluded fronts and associated extra-tropical cold core low pressure systems. Northern 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. 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. 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 © 1988-2003 by Thomas F. Giella and the Florida Space And Atmospheric Weather Institute, all rights reserved. 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 Plant City, FL, USA EL87WX Yaesu FT-840 & PSK31 Digital Mode E Group http://groups.yahoo.com/group/yaesu_ft840 160 Meter Amateur Radio Resources & More http://www.kn4lf.com/kn4lf.htm Daily Solar Space Weather & Geomagnetic Data Archive http://www.kn4lf.com/kn4lf5.htm HF/MF Radio Propagation Theory Notes http://www.kn4lf.com/kn4lf8.htm Florida Space & Atmospheric Weather Institute http://www.kn4lf.com/fsawi.htm Florida Daily Weather Discussion http://www.kn4lf.com/sub/fmci17.htm Friend Website Design Studio http://www.kn4lf.com --- Outgoing mail is certified Virus Free Thanks To Grisoft AVG. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.550 / Virus Database: 342 - Release Date: 12/9/2003 ---[Start Commercial]--------------------- World Radio TV Handbook 2004 is coming out! Preorder yours now! Only $20.97 through us. http://www.amazon.com/exec/obidos/ASIN/0823059685/hardcoredxcom ---[End Commercial]----------------------- ________________________________________ Hard-Core-DX mailing list [EMAIL PROTECTED] http://dallas.hard-core-dx.com/mailman/listinfo/hard-core-dx http://www.hard-core-dx.com/ _______________________________________________ THE INFORMATION IN THIS ARTICLE IS FREE. It may be copied, distributed and/or modified under the conditions set down in the Design Science License published by Michael Stutz at http://dsl.org/copyleft/dsl.txt