Solar Terrestrial Activity Report [Image] Last update July 11, 2000 at 04:55 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 active on July 10. Solar wind speed ranged between 353 and 544 km/sec. The disturbance related to a full halo CME observed on July 7 arrived at 05:55 at SOHO and produced a sudden impulse at Earth at approximately 06:40 UTC. Initially the interplanetary magnetic field was strongly southwards, which would normally have resulted in minor to major storming. The disturbance peaked at the active level. Another disturbance could impact Earth soon as solar wind density is very high as I write this. Solar flare activity was high. Solar flux was 244.5, the planetary A index was 19 (3-hour K indices: 2343 4443, Boulder K indices: 1343 4433). Region 9066 decayed into spotless plage. Region 9067 was quiet and stable. Region 9068 decayed slowly and was quiet. Occasional C flares and minor M flares are possible. Region 9069 developed further and could produce additional minor M class flares. Region 9070 developed slowly and has a good chance of producing another minor M flare. Region 9071 decayed into spotless plage. Region 9073 was mostly unchanged and quiet. C class flares are possible, as is an isolated minor M class flare. Region 9074 was quiet and stable. Region 9075 once again decayed into spotless plage. Region 9076 was quiet and stable. Region 9077 developed further into a very complex and large region with a strong magnetic delta configuration. Major M and X class flares are possible, as is a large proton flare. Regions 9078, 9079 and 9080 were quiet and stable. An active and interesting region is just behind the northeast limb. Flares and CMEs A total of 3 C and 5 M class events were observed on July 10. Region 9077 produced a C6.0 flare at 01:13, a long duration M1.1 event peaking at 10:56, an M1.4 flare at 14:26 and a long duration major M5.7/2B flare peaking at 21:42 UTC. Strong type II and IV sweeps were recorded during the major flare. A full halo coronal mass ejection was observed in LASCO C3 starting at 22:18 UTC. Most of the mass headed off towards the northeast, however, there is a possibility for minor or major storming at Earth on July 13 or 14. Region 9070 generated a C3.5 flare at 07:57 and an M1.9/SB flare at 20:05 UTC. Region 9066 was the source of a C3.2 flare at 16:51 UTC. Region 9069 produced an M1.8/1N flare at 18:38 UTC. A large prominence in the northeast quadrant erupted. The eruption started slowly at approximately 13h UTC and peaked at about 20h UTC. July 9: 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. The background x-ray flux is at the class C3 level. Coronal holes A small coronal hole just to the west of region 9077 will rotate into a geoeffective position on July 12 and could cause unsettled to active intervals on July 15. Forecast The geomagnetic field is expected to be unsettled to major storm on July 11-13. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor. 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 Location region numbered no. at Area Classification Comment sunspots midnight 9065 20000629 N24W65 plage 9066 20000629 N13W68 plage 9067 20000629 1 S19W72 0130 HSX 9068 20000701 19 S18W53 0300 DAI 9069 20000701 21 S17W39 0370 EAI 9070 20000702 27 N19W38 0330 EAC beta-gamma 9071 20000705 N24W89 plage 9072 20000705 N16W50 plage 9073 20000705 18 S19W23 0170 ESO 9074 20000705 4 N13E02 0020 CSO 9075 20000706 N06E17 plage 9076 20000706 1 S23E19 0020 HSX 9077 20000707 28 N17E44 0950 FKC beta-gamma-delta 9078 20000707 1 S14E28 0030 HRX 9079 20000709 1 S29E51 0070 HSX 9080 20000709 1 N25E68 0030 HSX Total number of sunspots: 122 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 2000.07 183.7 (1) 67.1 (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]