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Internet Message Format | 1991-07-04 | 31KB

Return-path: <ota+space.mail-errors@andrew.cmu.edu> X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/kcR0:ui00WBw4GS057>; Fri, 5 Jul 91 01:25:14 -0400 (EDT) Message-ID: <AcR0-hW00WBwAGQE59@andrew.cmu.edu> Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, 5 Jul 91 01:25:03 -0400 (EDT) Subject: SPACE Digest V13 #781 SPACE Digest Volume 13 : Issue 781 Today's Topics: Re: Magellan Images Solar Terrestrial Forecast and Review Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 20 Jun 91 14:35:05 GMT From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!dsinc!ub!bowen@ucbvax.Berkeley.EDU (Devon E Bowen) Subject: Re: Magellan Images In article <1991Jun20.011815.9421@nntp-server.caltech.edu>, steinly@zeppo.tapir.Caltech.EDU (Steinn Sigurdsson) writes: |> Yay! he's back, the forces of democracy and progress have |> overcome the evil bureaucracy ;-) Now can we stop asking where Ron |> Baalke is? You people are so naive. You really think this is the REAL Ron Baalke don't you?! I have it from a very good source that Ron is in a prison camp some- where in a Mexican desert. This is obviously an imposter created when the government realized we were catching on. This *simply can't be him*. I say we keep pressing JPL until they talk! Welcome back Ron. It's nice to shut the rest of these people up... Devon ------------------------------ Date: Fri, 21 Jun 91 00:48:47 MDT From: oler <@BITNET.CC.CMU.EDU:oler@HG.ULeth.CA> (CARY OLER) Subject: Solar Terrestrial Forecast and Review X-St-Vmsmail-To: st%"space+@andrew.cmu.edu" --- SOLAR TERRESTRIAL FORECAST AND REVIEW --- June 21 to June 30, 1991 Report Released by Solar Terrestrial Dispatch P.O. Box 357, Stirling, Alberta, Canada T0K 2E0 --------- SOLAR TERRESTRIAL REVIEW FOR 31 MAY TO 20 JUNE A magnificent barrage of very powerful solar flares is the highlight of this weeks STFR report. The first signs of significant activity were observed on 01 June. An optically uncorrelated class X12+ x-ray event was observed at 15:20 UT on 01 June. This event was accompanied by a large spray off the northeast limb. Over the next several days, Region 6659 rotated into view at a north solar latitude of 31 degrees, in the vicinity of old Region 6619. On 04 June, Region 6659 unleashed another powerful class X12+/3B x-ray flare which saturated the GOES sensors and was associated with strong radio bursts. This event had a very high integrated x-ray flux, estimated at 3.53 joules per square meter. The delay of several days between these powerful solar flares is evidence of a magnetic "store and release" mechanism where magnetic energy is stored until it surpasses a trigger threshold, afterwhich it suddenly and explosively releases it all. This method of energy build-up and release was observed throughout the transit of Region 6659 across the solar disk. On 06 June, a massive solar flare ripped out of Region 6659, which again, saturated the GOES satellite sensors at a level greater than X12. This flare was optically rated a 4B event (very large in area and brilliant). This event had major Type III, IV and V sweeps with an importance 2 Type II sweep. These large solar flares produced copious quantities of high-energy solar protons which engulfed the Earth. Protons at geosynchronous altitudes passed event thresholds at 13:00 UT on 31 May and would not return back below threshold values for a stable period of time until 19 June, almost three weeks later. The peak proton flux of 1,400 pfu was observed at greater than 10 MeV on 15 June at 19:50 UT. The intensity of the solar flaring as was observed from Region 6659 is only rarely seen. Great Flares (as they are called) have saturated the GOES x-ray sensors before (for example, during the flare storm period of March 1989). However, never before in this solar cycle have the GOES x-ray sensors been saturated so many times in such a short period of time. Even the region which spawned the large flares in 1989 could not match the stability and power unleashed by Region 6659. Region 6659 rotated beyond the west limb and out of view on 16/17 June. By that time, it was showing signs of decay and penumbral fragmentation, but was still able to produce another major M-class flare before it finally departed from view. This region is not expected to return in a configuration capable of producing powerful major flares, although occassional M-class flaring will be a possibility. It is due to return back into view on 01 June. A severe geomagnetic storm was observed on 05 June. The activity began on 04 June at approximately 16:00 UT. Minor storming was observed until near 06:00 UT on 05 June, when major to severe geomagnetic storming began to be observed over all latitudes. This event produced planetary magnetic A-indices higher than anything observed since the very severe geomagnetic storm of March 1989. The planetary A-index for 05 June was 150 (compared to 246 for 13 March 1989). K-indices between 6 and 9 were consistently observed throughout the UT day of 05 June. Minor to major geomagnetic storming was the dominant feature over the last two weeks. Minor to severe storming occurred from 04 to 07 June, 09 to 13 June, and the last minor geomagnetic storm was observed on 17 June. Conditions since then have been generally unsettled to active. A major auroral storm accompanied the severe geomagnetic storm of 05 June. Auroral activity was observed as far south as Kansas, New Mexico, California and other low latitude states in the U.S.. Many confirmed sightings of aurorae were also received from Australia. There has even been an unconfirmed report of visible auroral activity from Mexico. Repeated observations of auroral activity were observed throughout the previous two week period. Region 6659 was expected to produce several powerful auroral storms. However, the unfortunate timing of the interplanetary shockwaves prevented significant wide-spread auroral observations over the U.S., Australia and New Zealand. Weather conditions over Europe were not favorable for viewing auroral activity during most of the intense storm periods. The most intense periods of auroral and geomagnetic activity occurred during the daylight hours over North America after the 05 June event. By the time evening twilight had ended for observers in North America, the most intense phase of the storming had ended and auroral activity died down. For these reasons, significant auroral displays over the U.S. and Australia were not possible after the 05 June event, even though a high probability existed. Strong HF radio impacts were observed as Region 6659 crossed the solar disk. Aside from frequent major SIDs and SWFs generated by the powerful x-ray flares from this region, significant polar cap absorption (PCA) blacked out radio paths over the polar and some high latitude regions. Persistent absorption from proton activity severely disrupted communications from, through, or near the polar regions. There were a few brief periods (between proton waves) where absorption levels abated long enough to permit sporadic and unstable communications from the polar regions. However, these conditions did not last long, for as soon as Region 6659 spawned another powerful flare, the Earth was quickly engulfed in another stream of protons which ionized the polar ionosphere sufficiently to absorb most radio signals. Improvements began to be observed after Region 6659 rotated behind the west limb of the Sun. Between 18 and 20 June, significant ionospheric recovery took place. At the present time, conditions are normal over the low, middle and high latitude regions, with near normal conditions over the polar regions. VHF backscatter communications were possible and were observed on 05 June, in conjunction with the severe geomagnetic storm. Repeated observations of auroral backscatter were observed with each period of major geomagnetic storming, although conditions were never as favorable as was observed during the 05 June event. This period of major flare and significant geophysical activity was one of the most significant periods since the March 1989 activity. Although it is almost impossible to tell, there will continue to be a threat for similar unexpected outbursts of activity over the next year or two. There will also continue to be a threat for severe geomagnetic storms and impressive auroral displays for several more years. Based on the previous solar cycles and activity models, the next three to four years (until 1994 or 1995) will be statistically significant years for experiencing possible major to severe geomagnetic activity and global auroral storms. SHORT TERM SOLAR TERRESTRIAL FORECAST Solar activity is expected to remain generally low to moderate over the next week. Old Regions 6652 and 6654 are due to return within the next 24 to 48 hours and may return in a form capable of supporting occassional low-level M-class flares. We are now very near the minimum rotational 10.7 cm radio flux values and should begin to observe increased indices over the next 24 to 72 hours (by 23 June). Several major flares may be observed during this next solar rotation. But overall, activity is expected to remain generally moderate, with only occassional low-level M-class flares. Geomagnetic activity is expected to increase to generally active levels from 21 to 24 June as recurrent coronal holes begin to influence our near-Earth environment. There is a chance for middle and high latitude minor geomagnetic storming during this period, with a slight risk for major storm periods over the high latitude regions. Conditions should remain at generally active to minor storm levels over the middle latitudes during this period. Northerly middle and high latitude regions should witness moderate levels of auroral activity on the evenings of 21 through 23 June. There are also expected to be brief periods of high auroral activity over the high latitude regions. However, lunar phase will progressively inhibit attempts to view auroral activity over all latitudes. HF propagation conditions will continue at near normal levels for this time of year over the low and middle latitudes, with a possibility for some minor degradation during the peak hours of geomagnetic activity. Overall, conditions should be fair to good, with improvements occurring toward the end of June. VHF propagation conditions are expected to be normal over all latitudes. The only possible exception will be the high latitude regions where some minor signal anomalies may be observed during the more intense periods of geomagnetic and auroral activity. SUMMARY OF ALL ACTIVE REGIONS VISIBLE ON THE SOLAR DISK AS OF 21 JUNE Region # Location LO Area Class LL Spots Magnetic Type -------- -------- --- ---- ----- -- ----- ------------- 6678 S28W18 114 0030 BXO 10 004 BETA 6680 S14W50 146 0240 CAO 06 010 BETA 6681 N09E05 091 0570 DAI 06 016 BETA 6682 S11W36 132 0930 DKI 08 032 BETA 6685 N22E44 052 0270 HSX 02 001 ALPHA 6686 S16E39 057 0240 DAO 07 008 BETA 6687 N16E12 084 0120 CAO 05 012 BETA NOTES: Area is in million square kilometers. Angular extent (LL) and solar longitude (LO) are in degrees. For more information regarding the terminology used above, request the Glossary of Solar Terrestrial Terms from: "oler@hg.uleth.ca". H-ALPHA PLAGES WITHOUT SPOTS. LOCATIONS VALID AS OF 00:00 UT ON 21 JUNE REGION LOCATION LO COMMENTS (IF ANY) ------ -------- --- ------------------------------- 6673 S22W70 166 NONE 6677 S13W55 151 6683 S15W71 167 6684 S15E10 086 6688 S27E30 066 ACTIVE REGIONS DUE TO RETURN BETWEEN 21 JUNE AND 23 JUNE Region Latitude Longitude (Helio.) ------ -------- --------- 6652 S10 356 6654 N06 352 6655 S09 340 NOTES: For definitions regarding the above, request the "Glossary of Solar Terrestrial Terms" from "oler@hg.uleth.ca". GRAPHICAL ANALYSIS OF RECENT PLANETARY (GLOBAL) GEOMAGNETIC ACTIVITY Cumulative Geomagnetic Activity History Peak Planetary Geomagnetic Activity during the past 96 hours ____________________________________________________________________ | EXTREMELY SEVERE | | | | | HIGH | | VERY SEVERE STORM | | | | | HIGH | | SEVERE STORM | | | | | MODERATE | | MAJOR STORM | **| | | | LOW - MOD. | | MINOR STORM | *****|* | | | LOW | | VERY ACTIVE | *****|**** * |********| | NONE | | ACTIVE | *******|********|********|** ***| NONE | | UNSETTLED |********|********|********|********| NONE | | QUIET |********|********|********|********| NONE | | VERY QUIET |********|********|********|********| NONE | |-------------------|--------|--------|--------|--------|------------| | Geomagnetic Field | Mon. | Tue. | Wed. | Thu. | Anomaly | | Conditions | Given in 3-hourly UT intervals | Intensity | |____________________________________________________________________| NOTES: The data above represents preliminary planetary geomagnetic activity. Data from many magnetic observatories around the world are used in constructing the above chart. The first graph line for each day represents geomagnetic activity which occurred between 00 UT and 03 UT. The second graph line represents activity which occurred between 03 UT and 06 UT, etc. For information regarding the interpretation and/or use of these charts, send a request for the document "Understanding Solar Terrestrial Reports" to: oler@hg.uleth.ca. PEAK PLANETARY 10-DAY GEOMAGNETIC ACTIVITY OUTLOOK (21 JUNE - 30 JUNE) ________________________________________________________________________ | EXTREMELY SEVERE | | | | | | | | | | | HIGH | | VERY SEVERE STORM | | | | | | | | | | | HIGH | | SEVERE STORM | | | | | | | | | | | MODERATE | | MAJOR STORM | | | | | | | | | | | LOW - MOD. | | MINOR STORM | |** |** | | | | | | | | LOW | | VERY ACTIVE | **|***|***|** |** | | | | | | NONE | | ACTIVE |***|***|***|***|***|***| * | * | | | NONE | | UNSETTLED |***|***|***|***|***|***|***|***|***|***| NONE | | QUIET |***|***|***|***|***|***|***|***|***|***| NONE | | VERY QUIET |***|***|***|***|***|***|***|***|***|***| NONE | |-------------------|---|---|---|---|---|---|---|---|---|---|------------| | Geomagnetic Field |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| Anomaly | | Conditions | Given in 8-hour intervals | Intensity | |________________________________________________________________________| CONFIDENCE LEVEL: 65% NOTES: Predicted geomagnetic activity is based heavily on recurrent phenomena. Transient energetic solar events cannot be predicted reliably over periods in excess of several days. Hence, there may be some deviations from the predictions due to the unpredictable transient solar component. GRAPHICAL ANALYSIS OF SOLAR ACTIVITY OVER THE PAST 60 DAYS Cumulative Graphical Analysis of Solar Activity ____________________________________________________________ 252| * | HIGH 243| F = Major Flare(s) F * * | Moderate 234| * F F*F *F*F | Moderate 225| **** F F F*F**F*F* | Moderate 216| ***** FF*FF*F*F**F*F*F | Moderate 207| ******F* FFF*FF*F*F**F*F*F | Moderate 198| *******F* FFF*FF*F*F**F*F*FF | Moderate 188| *******F** *FFF*FF*F*F**F*F*FFF | Low 179| ********F**F **FFF*FF*F*F**F*F*FFF* | Low 170| ********F**F* ***FFF*FF*F*F**F*F*FFF*F** | Low 161|* * *********F**F*F* ***FFF*FF*F*F**F*F*FFF*F***| Low 152|* ***************F**F*F* *****FFF*FF*F*F**F*F*FFF*F***| Low 143|** ****************F**F*F*********FFF*FF*F*F**F*F*FFF*F***| Low 134|*********************F**F*F*********FFF*FF*F*F**F*F*FFF*F***| Low 125|*********************F**F*F*********FFF*FF*F*F**F*F*FFF*F***| Very Low ------------------------------------------------------------ Cumulative 60 day Solar Activity Record Start Date: April 22, 1991 NOTES: Left-hand column digits represent the 10.7 cm solar radio flux obtained from Ottawa. The right-hand column describes the relative solar activity for that period based on the average number of major and minor flares that can be expected for related solar flux values. Plot lines labeled with the letter "F" represent days where at least one major flare occurred (ie. class M5 or greater flare). GRAPHICAL 20-DAY SOLAR ACTIVITY PREDICTION Solar Activity _________________________________________________________________ | 275 | | | | | | | | | | | | | | | | | | | | | | 265 | | | | | | | | | | | | | | | | | | | | | | 254 | | | | | | | | | | | | | | | | | | | | | | 244 | | | | | | | | | | | | | | | | | | | | | | 233 | | | | | | | | | | | |**|**|**|**| | | | | | | 223 | | | | | | | | | | |**| | | | |**|**| | | | | 213 | | | | | | | | | |**| | | | | | | |**| | | | 202 | | | | | | | |**|**| | | | | | | | | |**| | | 192 | | | | | |**|**| | | | | | | | | | | | |**| | 181 | | | |**|**| | | | | | | | | | | | | | | | | 171 | |**|**| | | | | | | | | | | | | | | | | | | 160 |**| | | | | | | | | | | | | | | | | | | | | 150 | | | | | | | | | | | | | | | | | | | | | |-----|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--| |Solar|21|22|23|24|25|26|27|28|29|30|01|02|03|04|05|06|07|08|09|10| |Flux | June | July | ----------------------------------------------------------------- CONFIDENCE LEVEL: 65% HF RADIO SIGNAL PROPAGATION PREDICTIONS (21 JUNE - 30 JUNE) High Latitude Paths ________________________________________________________ | EXTREMELY GOOD | | | | | | | | | | | | VERY GOOD | | | | | | | | | | | CONFIDENCE | GOOD | | | | | | | | | | | LEVEL | FAIR |* *| | | | *|* *|* *|***|***|***| ------- | POOR | * |***|***|***|** | * | * | | | | 65% | VERY POOR | | | | | | | | | | | | EXTREMELY POOR | | | | | | | | | | | |----------------|---|---|---|---|---|---|---|---|---|---| | PROPAGATION |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| | QUALITY | Given in 8-Hour UT Intervals | -------------------------------------------------------- Middle Latitude Paths ________________________________________________________ | EXTREMELY GOOD | | | | | | | | | | | | VERY GOOD | | | | | | | | | | | CONFIDENCE | GOOD |***| *| *|* *|* *|***|***|***|***|***| LEVEL | FAIR | |** |** | * | * | | | | | | ------- | POOR | | | | | | | | | | | 70% | VERY POOR | | | | | | | | | | | | EXTREMELY POOR | | | | | | | | | | | |----------------|---|---|---|---|---|---|---|---|---|---| | PROPAGATION |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| | QUALITY | Given in 8-Hour UT Intervals | -------------------------------------------------------- Low Latitude Paths ________________________________________________________ | EXTREMELY GOOD | | | | | | | | | | | | VERY GOOD | | | | | | | | | | | CONFIDENCE | GOOD |***|* *|* *|***|***|***|***|***|***|***| LEVEL | FAIR | | * | * | | | | | | | | ------- | POOR | | | | | | | | | | | 75% | VERY POOR | | | | | | | | | | | | EXTREMELY POOR | | | | | | | | | | | |----------------|---|---|---|---|---|---|---|---|---|---| | PROPAGATION |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| | QUALITY | Given in 8-Hour UT Intervals | -------------------------------------------------------- NOTES: NORTHERN HEMISPHERE SOUTHERN HEMISPHERE High latitudes >= 55 deg. N. | High latitudes >= 55 deg. S. Middle latitudes >= 40 < 55 deg. N. | Middle latitudes >= 35 < 55 deg. S. Low latitudes < 40 deg. N. | Low latitudes < 35 deg. S. POTENTIAL VHF DX PROPAGATION PREDICTIONS (21 JUNE - 30 JUNE) INCLUDES SID AND AURORAL BACKSCATTER ENHANCEMENT PREDICTIONS HIGH LATITUDES __________________________________________________ ___________________ | SIGNAL | Given in 8 hour local time intervals | | SID ENHANCEMENT | | QUALITY |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| |F|S|S|M|T|W|T|F|S|S| |__________|___|___|___|___|___|___|___|___|___|___| |-|-|-|-|-|-|-|-|-|-| | VERY GOOD| | | | | | | | | | | 0%|*|*|*|*|*|*|*|*|*|*| |ABOVE NORM| | | | | | | | | | | 20%|*|*|*|*|*|*|*|*|*|*| | NORMAL|***| **| **|***|***|***|***|***|***|***| 40%| | | | | | | | | | | |BELOW NORM| |* |* | | | | | | | | 60%| | | | | | | | | | | | VERY POOR| | | | | | | | | | | 80%| | | | | | | | | | | | BLACKOUT| | | | | | | | | | |100%| | | | | | | | | | | |==========|===|===|===|===|===|===|===|===|===|===| |-------------------| | 100% | | | | | | | | | | |100%| | | | | | | | | | | | 80% | | | | | | | | | | | 80%| | | | | | | | | | | | 60% | | | | | | | | | | | 60%| | | | | | | | | | | | 40% | | | | | | | | | | | 40%| |*|*|*| | | | | | | | 20% |***|***|***|***|***|***| * | * | * | * | 20%|*|*|*|*|*|*|*|*|*|*| | 0% |***|***|***|***|***|***|***|***|***|***| 0%|*|*|*|*|*|*|*|*|*|*| |----------+---|---|---|---|---|---|---|---|---|---| |-|-|-|-|-|-|-|-|-|-| |CHANCE OF |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| |F|S|S|M|T|W|T|F|S|S| | VHF DX | Given in 8 hour local time intervals | |AURORAL BACKSCATTER| |__________|_______________________________________| |___________________| MIDDLE LATITUDES __________________________________________________ ___________________ | SIGNAL | Given in 8 hour local time intervals | | SID ENHANCEMENT | | QUALITY |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| |F|S|S|M|T|W|T|F|S|S| |__________|___|___|___|___|___|___|___|___|___|___| |-|-|-|-|-|-|-|-|-|-| | VERY GOOD| | | | | | | | | | | 0%|*|*|*|*|*|*|*|*|*|*| |ABOVE NORM| | | | | | | | | | | 20%|*|*|*|*|*|*|*|*|*|*| | NORMAL|***|***|***|***|***|***|***|***|***|***| 40%| | | | | |*|*|*|*|*| |BELOW NORM| | | | | | | | | | | 60%| | | | | | | | | | | | VERY POOR| | | | | | | | | | | 80%| | | | | | | | | | | | BLACKOUT| | | | | | | | | | |100%| | | | | | | | | | | |==========|===|===|===|===|===|===|===|===|===|===| |-------------------| | 100% | | | | | | | | | | |100%| | | | | | | | | | | | 80% | | | | | | | | | | | 80%| | | | | | | | | | | | 60% | | | | | | | | | | | 60%| | | | | | | | | | | | 40% | | | | | | | | | | | 40%| | | | | | | | | | | | 20% | **|***|***|***|***| **| **| **| **| **| 20%| |*|*|*| | | | | | | | 0% |***|***|***|***|***|***|***|***|***|***| 0%|*|*|*|*|*|*|*|*|*|*| |----------+---|---|---|---|---|---|---|---|---|---| |-|-|-|-|-|-|-|-|-|-| |CHANCE OF |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| |F|S|S|M|T|W|T|F|S|S| | VHF DX | Given in 8 hour local time intervals | |AURORAL BACKSCATTER| |__________|_______________________________________| |___________________| LOW LATITUDES __________________________________________________ ___________________ | SIGNAL | Given in 8 hour local time intervals | | SID ENHANCEMENT | | QUALITY |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| |F|S|S|M|T|W|T|F|S|S| |__________|___|___|___|___|___|___|___|___|___|___| |-|-|-|-|-|-|-|-|-|-| | VERY GOOD| | | | | | | | | | | 0%|*|*|*|*|*|*|*|*|*|*| |ABOVE NORM| | | | | | | | | | | 20%|*|*|*|*|*|*|*|*|*|*| | NORMAL|***|***|***|***|***|***|***|***|***|***| 40%| | | | | |*|*|*|*|*| |BELOW NORM| | | | | | | | | | | 60%| | | | | | | | | | | | VERY POOR| | | | | | | | | | | 80%| | | | | | | | | | | | BLACKOUT| | | | | | | | | | |100%| | | | | | | | | | | |==========|===|===|===|===|===|===|===|===|===|===| |-------------------| | 100% | | | | | | | | | | |100%| | | | | | | | | | | | 80% | | | | | | | | | | | 80%| | | | | | | | | | | | 60% | | | | | | | | | | | 60%| | | | | | | | | | | | 40% | | | | | | | | | | | 40%| | | | | | | | | | | | 20% | * | * | * | * | * | **| **| **| **| **| 20%| | | | | | | | | | | | 0% |***|***|***|***|***|***|***|***|***|***| 0%|*|*|*|*|*|*|*|*|*|*| |----------+---|---|---|---|---|---|---|---|---|---| |-|-|-|-|-|-|-|-|-|-| |CHANCE OF |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| |F|S|S|M|T|W|T|F|S|S| | VHF DX | Given in 8 hour local time intervals | |AURORAL BACKSCATTER| |__________|_______________________________________| |___________________| NOTES: These VHF DX prediction charts are defined for the 50 MHz to 220 MHz bands. They are based primarily on phenomena which can affect VHF DX propagation globally. They should be used only as a guide to potential DX conditions on VHF bands. Latitudinal boundaries are the same as those for the HF predictions charts. For more information, request the document "Understanding Solar Terrestrial Reports" from: "oler@hg.uleth.ca". AURORAL ACTIVITY PREDICTIONS (21 JUNE - 30 JUNE) High Latitude Locations ________________________________________________________ | EXTREMELY HIGH | | | | | | | | | | | CONFIDENCE | VERY HIGH | | | | | | | | | | | LEVEL | HIGH | | | | | | | | | | | ------- | MODERATE | * |***|***| * | * | | | | | | 65% | LOW |***|***|***|***|***|***| * | * | * | * | | NOT VISIBLE |***|***|***|***|***|***|***|***|***|***| |----------------|---|---|---|---|---|---|---|---|---|---| | AURORAL |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| | INTENSITY | Eve.Twilight/Midnight/Morn.Twilight | -------------------------------------------------------- Middle Latitude Locations ________________________________________________________ | EXTREMELY HIGH | | | | | | | | | | | CONFIDENCE | VERY HIGH | | | | | | | | | | | LEVEL | HIGH | | | | | | | | | | | ------- | MODERATE | | * | * | | | | | | | | 65% | LOW | * |***|***|***| * | | | | | | | NOT VISIBLE |***|***|***|***|***|***|***|***|***|***| |----------------|---|---|---|---|---|---|---|---|---|---| | AURORAL |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| | INTENSITY | Eve.Twilight/Midnight/Morn.Twilight | -------------------------------------------------------- Low Latitude Locations ________________________________________________________ | EXTREMELY HIGH | | | | | | | | | | | CONFIDENCE | VERY HIGH | | | | | | | | | | | LEVEL | HIGH | | | | | | | | | | | ------- | MODERATE | | | | | | | | | | | 75% | LOW | | | | | | | | | | | | NOT VISIBLE |***|***|***|***|***|***|***|***|***|***| |----------------|---|---|---|---|---|---|---|---|---|---| | AURORAL |Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun| | INTENSITY | Eve.Twilight/Midnight/Morn.Twilight | -------------------------------------------------------- NOTE: For more information regarding these charts, send a request for the document, "Understanding Solar Terrestrial Reports" to: oler@hg.uleth.ca. ** End of Report ** ------------------------------ End of SPACE Digest V13 #781 *******************