Solar Terrestrial Activity Report [Image] Last update November 26, 2000 at 04:40 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 25. Solar wind speed ranged between 371 and 468 km/sec. Solar flare activity was high. Solar flux was 201.1 (the average of the 18 and 22h UTC measurements, the 20h UTC measurement was highly influenced by flare activity), the planetary A index was 7 (3-hour K indices: 3301 1232, Boulder K indices: 3311 1132). Region 9231 rotated off the visible disk. Region 9233 decayed and was quiet, this region and region 9235 will rotate over the west limb on November 27. Region 9235 decayed further and was quiet. Region 9236 developed slowly and is still very complex with a strong magnetic delta configuration. Further X class flares are possible and likely. Region 9239 was quiet and stable. Region 9240 has a large leader spot and may be capable of producing further major flares. Region 9241 decayed into spotless plage. Region 9242 decayed and was quiet. Flares and CMEs A total of 4 C, 2 M and 1 X class events were recorded on November 25. Region 9240 produced a long duration major M8.2/2N event at 01:31 UTC. This event was accompanied by a strong type II sweep and a moderate long lasting type IV sweep. A CME may have been produced as well and could impact Earth on November 27. Region 9236 generated an M3.5/2N flare at 09:20 (associated with another full halo CME), a C3.3 flare at 15:35, a C1.9 flare at 15:56, a C3.2 flare at 17:28 and a major impulsive X1.9/2B flare at 18:44 UTC. A strong type II sweep was recorded and a full halo CME was observed in LASCO images. Amazingly, currently 6-7 CMEs are on their way towards Earth. It could be difficult to discern the impact times of some of the CMEs, and some of the faster CMEs could even catch up with the one just ahead of it. Complex geomagnetic disturbance patterns are likely and the geomagnetic field is likely to range between active and very severe storm levels today as the first CMEs arrive. Updates will be posted today ... November 24: Region 9236 produced a major impulsive X2.0/3B flare at 05:01 (associated with a strong type II sweep and a fast full halo CME), 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. 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. The background x-ray flux is at the class B8 level. Coronal holes A trans equatorial coronal hole formed quickly over the past couple of days to the southeast of region 9236 and was in a geoeffective position on November 25. This would normally result in a few unsettled to active intervals on November 28, but the effects are likely to be unnoticed because of the influence from all the CMEs currently heading our way. Forecast The geomagnetic field is expected to be quiet to severe storm on November 26 and minor to very severe storm on November 27. 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 no. Location at region numbered sunspots midnight Area Classification Comment 9231 20001113 2 S20W91 0080 CAO 9232 20001113 N25W84 plage 9233 20001114 2 N15W70 0050 CSO 9235 20001116 1 N12W70 0060 HAX 9236 20001118 29 N22W21 0580 FKC gamma-delta 9238 20001120 S22W61 plage 9239 20001121 1 S21E24 0140 HSX 9240 20001122 4 N09E34 0220 CHO beta-gamma 9241 20001123 N21W46 plage 9242 20001124 1 N21E57 0020 AXX Total number of sunspots: 40 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) 2000.11 175.7 (1) 125.9 (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]