Solar Terrestrial Activity Report [Image] Last update November 1, 2001 at 02:00 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update October 3, 2001)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update October 3, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update October 3, 2001)] [Historical solar and geomagnetic data charts 1954-2001 (last update October 16, 2001)] Recent development The geomagnetic field was quiet to unsettled on October 31. Solar wind speed ranged between 300 and 414 km/sec. A weak solar wind shock was observed at SOHO at 12:49 UTC with an abrupt increase in solar wind speed from 315 to 410 km/sec. Although the shock was weak the interplanetary magnetic field has been mostly southwards since the impact and could cause isolated active to minor storming conditions early on November 1. The source of the shock is uncertain, there was no obvious halo CME on October 27/28. Solar flare activity was moderate. Solar flux was 221.1, the planetary A index was 9 (3-hour K indices: 1120 3333, Boulder K indices: 2221 2233). Region 9676 decayed and was spotless by early afternoon. Region 9678 decayed further and was quiet. Region 9679 decayed and was spotless by noon. Region 9681 was spotless all day in all available images. Region 9682 temporarily lost its magnetic delta structure but this appeared to have redeveloped by late evening. Major flares are possible. Region 9683 decayed and was spotless by noon. Region 9684 was quiet and stable. M class flares are possible. New regions 9685 and 9686 rotated into view at the northeast limb. An interesting is rotating into view at the southeast limb. The region could be capable of producing major flares. Flares and CMEs A total of 3 C and 3 M class events were recorded on October 31. Region 9682 produced an M3.2/1N flare at 08:09 and a C5.6 flare at 16:05 UTC. Optically unaccounted M1.5 and M1.0 flares were recorded at 10:51 and 21:42 UTC respectively. 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 quiet to active on November 1 and quiet to unsettled on November 2. 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 9675 2001.10.20 S12W77 plage 9676 2001.10.20 1 N15W74 0010 HSX now spotless 9677 2001.10.21 N24W75 plage 9678 2001.10.23 17 N06W61 0450 EKO 9679 2001.10.23 6 S12W44 0020 BXO now spotless 9680 2001.10.23 N22W48 plage 9681 2001.10.25 1 S22W78 0000 AXX actually spotless 9682 2001.10.25 61 N11W10 1210 EKC beta-gamma-delta 9683 2001.10.26 3 N27W35 0010 BXO now spotless 9684 2001.10.27 27 N05E29 0470 EKI beta-gamma 9685 2001.10.31 5 N05E68 0030 CSO 9686 2001.10.31 1 N16E68 0050 HSX Total number of sunspots: 122 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.04 184.2 125.5 120.8 cycle 23 sunspot max. 2000.07 202.3 170.1 119.8 2000.09 182.1 109.7 116.3 (-2.3) 2000.10 167.4 99.4 114.5 (-1.8) 2000.11 178.8 106.8 112.7 (-1.8) 2000.12 173.6 104.4 112.0 (-0.7) 2001.01 166.6 95.6 108.7 (-3.3) 2001.02 146.6 80.6 104.1 (-4.6) 2001.03 177.7 113.5 104.8 (+0.7) 2001.04 177.7 107.7 (107.7 predicted, +2.9) 2001.05 147.1 96.6 (108.1 predicted, +0.4) 2001.06 173.0 134.0 (106.3 predicted, -1.8) 2001.07 131.3 82.2 (105.1 predicted, -1.2) 2001.08 162.9 106.8 (105.7 predicted, +0.6) 2001.09 233.2 150.7 (105.1 predicted, -0.6) 2001.10 207.6 (1) 197.0 (2) (102.3 predicted, -2.8) 1) Running average based on the daily 20:00 UT solar flux value at 2800 MHz. 2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official international sunspot number 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]