Solar Terrestrial Activity Report [Image] Last update February 10, 2001 at 07:20 UT. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update February 2, 2001) - Cycle 23 peaked in April 2000?] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update February 2, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update February 2, 2001)] [Historical solar and geomagnetic data charts 1954-2000 (last update January 18, 2001)] Recent development The geomagnetic field was quiet on February 9. Solar wind speed ranged between 391 and 448 km/sec. Solar flare activity was low. Solar flux was 162.4, the planetary A index was 4 (3-hour K indices: 0001 2222, Boulder K indices: 1002 2321). Region 9330 decayed further and could become spotless before rotating over the west limb on February 11. Region 9334 decayed slowly and was quiet. Region 9335 decayed slowly and was mostly quiet. Region 9338 developed quickly and is becoming fairly complex. A magnetic delta could form soon if development continues. M class flares are possible. Region 9339 decayed and was quiet, the region appears to be losing its trailing spots. Region 9341 was quiet and stable. Region 9344 was quiet and stable, the region is decaying and could soon become spotless. Region 9345 developed slowly and was quiet. New region 9346 emerged in the northwest quadrant but appears to be spotless already. New region 9347 rotated into view at the northeast limb at a low latitude. Another small region has rotated into view at the northeast limb but has not been numbered yet. Flares and CMEs A total of 5 C class events were recorded on February 8. Region 9335 produced a C1.0 flare at 17:27 UT. Region 9338 generated a C2.0 flare at 21:07, a C3.5 flare at 21:50 and a C3.1 long duration event peaking at 23:21 UT. The background x-ray flux is at the class B6 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on February 10-11. 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 9330 2001.01.30 6 N25W61 0070 DSO 9334 2001.02.01 15 N12W27 0100 ESI 9335 2001.02.03 9 N09W13 0060 DAO 9336 2001.02.03 S09W80 plage 9337 2001.02.03 S28W01 plage 9338 2001.02.04 16 S20W02 0080 DAO beta-gamma 9339 2001.02.04 11 S10E06 0200 EAO 9340 2001.02.05 S11W49 plage 9341 2001.02.06 3 S09W16 0010 CSO 9342 2001.02.06 S26E16 plage 9343 2001.02.07 N03W18 plage 9344 2001.02.08 4 N31E01 0020 CSO 9345 2001.02.08 7 S19E07 0040 CSO 9346 2001.02.09 4 N18W54 0030 BXO 9347 2001.02.09 4 N04E66 0090 CSO Total number of sunspots: 79 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.11 191.5 133.2 111.0 (+3.2) 1999.12 169.8 84.6 111.1 (+0.1) 2000.01 158.1 90.1 112.9 (+1.8) 2000.02 174.1 112.9 116.8 (+3.9) 2000.03 208.2 138.5 119.9 (+3.1) 120.8 (+0.9) 2000.04 184.2 125.5 cycle 23 peak candidate 2000.05 184.9 121.6 119.0 (-1.8) 2000.06 179.8 124.9 118.7 (-0.3) 2000.07 202.3 170.1 119.8 (+1.1) 2000.08 163.0 130.5 (119.7 predicted, -0.1) 2000.09 182.1 109.7 (118.4 predicted, -1.3) 2000.10 167.4 100.1 (116.7 predicted, -1.7) 2000.11 178.8 106.5 (114.8 predicted, -1.9) 2000.12 173.6 104.5 (112.2 predicted, -2.6) 2001.01 166.6 95.7 (108.7 predicted, -3.5) 2001.02 161.9 (1) 49.7 (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]