Solar Terrestrial Activity Report [Image] Last update November 25, 2000 at 04:45 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update November 1, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update November 1, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update November 1, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update October 20, 2000)] Recent development The geomagnetic field was quiet to unsettled on November 24. Solar wind speed ranged between 282 and 536 km/sec. A weak coronal stream caused a fairly steady increase in solar wind speed during the day. Solar flare activity was high. Solar flux was 197.1, the planetary A index was 9 (3-hour K indices: 1222 1333, Boulder K indices: 0223 2423). Region 9231 is rotating over the west limb and could produce C flares and perhaps an isolated minor M class flare. Region 9232 decayed into spotless plage. Region 9233 developed slowly and was quiet. Region 9235 decayed further and was quiet. Region 9236 is very complex with a fairly narrow opposite polarity band almost encircling the penumbra containing the huge leader spot. Further X class flares are possible but perhaps not at the extremely unusual rate of three in just a day. Region 9239 was quiet and stable. Region 9240 was mostly quiet but could produce C and M class flares. Region 9241 was quiet and stable. New region 9242 rotated into view at the northeast limb. Flares and CMEs A total of 5 C and 3 X class events were recorded on November 24. Region 9236 produced a C5.9 flare at 02:16, a C4.1 flare at 04:09, a major impulsive X2.0/3B flare at 05:01 (associated with a strong type II sweep and a fast full halo CME), a C4.2 flare at 07:47, a C2.4 flare at 11:38, a major impulsive X2.3/2B flare at 15:13 (associated with a strong type II sweep and another full halo CME) and finally another major flare, an X1.8/2N event at 21:59 UTC. Region 9236 was near the central meridian and all the CMEs are likely to be heading almost directly towards Earth. A long duration major M8.2 event peaked at 01:31 UTC and may have had its source in region 9240. A strong type II sweep was recorded and there was likely another geoeffective CME. November 23: Region 9238 was at the center of a fairly large filament eruption which recorded as a long duration C5.4/1F event and peaked at 05:47 UTC. A full halo CME was observed in LASCO images and the CME should impact Earth between noon on November 25 and noon on November 26. November 22: Region 9237 produced a C7.0/1N flare at 16:21 UTC, the flare was accompanied by a weak type II sweep. With the region only one day's rotation from the central meridian, a weak CME associated with the flare could easily be geoeffective and cause a minor geomagnetic disturbance on November 25. The background x-ray flux is at the class C1 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be unsettled to major storm on November 25 and active to severe storm on November 26. As many as 5 or 6 CMEs are heading towards Earth. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very 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 no. Location at region numbered sunspots midnight Area Classification Comment 9231 20001113 10 S24W74 0250 FKI 9232 20001113 N25W71 plage 9233 20001114 4 N15W55 0060 CSO 9235 20001116 2 N11W57 0080 CSO 9236 20001118 29 N21W08 0440 FKC gamma-delta 9238 20001120 S22W48 plage 9239 20001121 1 S20E36 0120 HSX 9240 20001122 4 N09E46 0180 CAO 9241 20001123 2 N21W33 0010 BXO 9242 20001124 2 N22E68 0040 BXO Total number of sunspots: 54 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 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 90.1 112.8 (+1.8) 2000.02 174.1 112.9 116.6 (+3.8) 2000.03 208.2 138.5 119.8 (+3.2) 2000.04 184.2 125.3 120.7 (+0.9) 2000.05 184.9 120.8 (119.6 predicted, -1.1) 2000.06 179.8 124.9 (120.3 predicted, +0.7) 2000.07 202.3 169.1 (122.4 predicted, +2.1) 2000.08 163.0 130.5 (122.5 predicted, +0.1) 2000.09 182.1 109.9 (121.0 predicted, -1.5) 2000.10 167.4 100.1 (119.8 predicted, -1.2) 2000.11 174.7 (1) 112.2 (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 noted in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]