Return-Path: Received: (qmail 30051 invoked from network); 21 Dec 2002 00:25:19 -0000 Received: from netmail01.services.quay.plus.net (212.159.14.219) by mailstore with SMTP; 21 Dec 2002 00:25:19 -0000 Received: (qmail 8253 invoked from network); 21 Dec 2002 00:25:14 -0000 Received: from post.thorcom.com (193.82.116.70) by netmail01.services.quay.plus.net with SMTP; 21 Dec 2002 00:25:14 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18PXRT-0005u2-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 21 Dec 2002 00:24:35 +0000 Received: from [12.145.226.11] (helo=mail2.gbronline.com) by post.thorcom.com with esmtp (Exim 4.10) id 18PXRT-0005tt-00 for rsgb_lf_group@blacksheep.org; Sat, 21 Dec 2002 00:24:35 +0000 Received: from nnn0hus [209.12.207.98] by mail2.gbronline.com (SMTPD32-7.13) id A4983C080062; Fri, 20 Dec 2002 18:23:52 -0600 Message-ID: <000701c2a887$3ffa1300$62cf0cd1@nnn0hus> From: "Thomas Giella, KN4LF" To: "a PSC E-List" , "a RSGB LF E-List" , "a Greyline Prop E-List" , "a HCDX Prop Channel" Date: Fri, 20 Dec 2002 19:23:54 -0500 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2720.3000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: KN4LF 7 Day MF Radio Propagation Outlook #2002-37 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=0.2 required=5.0tests=USER_AGENT_OEversion=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Seasons Greetrings To All! 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. 73, Thomas Giella KN4LF/NNN0HUS Plant City, FL, USA KN4LF 160 Meter Amateur Radio Resources And More: 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 Florida Daily WX Discussion: http://www.kn4lf.com/sub/fmci17.htm --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.431 / Virus Database: 242 - Release Date: 12/17/02