Solar Terrestrial Activity Report [Image] Last update July 10, 2000 at 04:40 UTC. Minor update posted at 06:07 UTC [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update July 1, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update July 1, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update July 1, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update April 12, 2000)] Recent development The geomagnetic field was quiet to unsettled on July 9. Solar wind speed ranged between 358 and 445 km/sec. Solar flare activity was high. Solar flux was 211.3, the planetary A index was 7 (3-hour K indices: 1122 2223, Boulder K indices: 1122 2212). Region 9066 was quiet and stable, as was region 9067. Region 9068 decayed slowly and was quiet. Occasional C flares and minor M flares are possible. Region 9069 developed further and was quiet. C and minor M class flares are possible. Region 9070 decayed slowly but could still produce M class flares. Region 9071 decayed slowly and was quiet. Region 9073 was mostly unchanged. C class flares are possible, as is an isolated minor M class flare. Region 9074 was quiet and stable. Region 9075 was spotless early in the day, then developed a couple of spots again. Region 9076 was quiet and stable. Region 9077 is a very complex and large region which developed quickly during the day. Additional major flares are possible, an X class flare is not unlikely. Region 9078 was quiet and stable. New region 9079 rotated into view at the southeast limb. New region 9080 rotated into view at the northeast limb. Comment added at 06:07 UTC on July 10: A fairly strong solar wind shock was observed at 05:59 UTC. Solar wind speed increased abruptly from 400 to 500 km/sec and the interplanetary magnetic field became strongly southwards. Major storming is possible when the disturbance reaches Earth at approximately 06:40 UTC. The source is the full halo CME observed on July 7. Flares and CMEs A total of 8 C and 1 M class events were observed on July 9. Region 9077 produced a C5.0 flare at 02:33, a C4.2 flare at 06:54, a major M5.7/1N flare at 07:23 (no significant CME was observed), a C4.4 flare at 12:13 and a C4.6 flare at 22:28 UTC. A weak type II sweep was recorded just after 11h UTC and was probably related to the observation of a full halo CME just before 12h UTC. As LASCO EIT images were unavailable at that time, it is hard to tell if the CME was caused by front or back side activity. If the source was on the visible disk the CME could impact Earth on July 12. July 8: There was some interesting eruptive activity in region 9070 at the very end of the day and early on July 9. A halo CME may have been a result of this activity and could impact Earth on July 11. July 7: The most interesting event of the day was a long duration C5.6 event just west of region 9070. This was actually a large filament eruption near the central meridian and stretching from the solar equator until just northwest of region 9071. The event started at 08:42 and ended at 10:11 UTC. A large full halo CME was observed in LASCO C2 images starting from 10:26 UTC. Earth will receive an impact, probably on July 10, unsettled to major storming is likely. The background x-ray flux is at the class C2 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to minor storm on July 10 due to effects from the arrival of a CME. Isolated major storm intervals are possible. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair. Coronal holes (1) Coronal mass M and X class flares (3) ejections (2) [Coronal hole indicator][CME indicator] [M and X class flare indicator] 1) Effects from a coronal hole could reach earth within the next 5 days. 2) Material from a CME is likely to impact earth within 96 hours. 3) There is a possibility of either M or X class flares within the next 48 hours. Green: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% probability. Active solar regions (Recent map) Solar Date Actual no. Location at region numbered sunspots midnight Area Classification Comment 9065 20000629 N24W52 plage 9066 20000629 2 N13W55 0010 BXO 9067 20000629 1 S18W56 0160 HSX 9068 20000701 22 S17W42 0320 DAI 9069 20000701 17 S17W25 0300 EAO 9070 20000702 26 N19W24 0320 EAC beta-gamma 9071 20000705 2 N24W76 0010 BXO 9072 20000705 N16W37 plage 9073 20000705 16 S19W09 0160 ESO 9074 20000705 5 N12E16 0020 BXO 9075 20000706 2 N06E31 0020 HSX 9076 20000706 1 S23E32 0020 HSX 9077 20000707 21 N18E55 0750 FKI beta-gamma 9078 20000707 5 S14E44 0020 BXO 9079 20000709 1 S29E65 0070 HSX 9080 20000709 1 N26E80 0060 HSX Total number of sunspots: 12 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.06 169.8 137.7 93.1 (+2.6) 1999.07 165.6 113.5 94.3 (+1.2) 1999.08 170.7 93.7 97.5 (+3.2) 1999.09 135.7 71.5 102.3 (+4.8) 1999.10 164.8 116.7 107.8 (+5.5) 1999.11 191.5 133.2 110.9 (+3.1) 1999.12 169.8 84.6 111.0 (+0.1) 2000.01 158.1 90.1 (110.9 predicted, -0.1) 2000.02 174.1 112.9 (113.7 predicted, +2.8) 2000.03 208.2 138.5 (117.9 predicted, +4.2) 2000.04 184.2 125.3 (120.0 predicted, +2.1) 2000.05 184.9 120.8 (120.8 predicted, +0.8) 2000.06 179.8 124.9 2000.07 176.9 (1) 59.6 (2) 1) Running average based on the daily 20:00 UTC solar flux value at 2800 MHz. 2) Unofficial, accumulated value. The official value is typically 25-40% less. This report has been prepared by Jan Alvestad. It is based partly on my own observations and interpretations, and partly on data from sources in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]