Solar Terrestrial Activity Report [Image] Last update October 29, 2001 at 03:25 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 major storm on October 28. Solar wind speed ranged between 351 and 532 km/sec. A strong solar wind shock was observed at SOHO at 02:33 UTC. The interplanetary magnetic field swung strongly southwards and remained southwards all day. The source of this disturbance was the halo CME originating from region 9672 on October 25. Solar flare activity was moderate. Solar flux was 227.2, the planetary A index was 41 (3-hour K indices: 2666 5443, Boulder K indices: 2566 4443). Region 9670 decayed further and rotated partly off the visible disk. Region 9672 decayed slowly and was quiet. There is still a chance of a major flare from this region. Region 9673 was quiet and stable, as were regions 9676 and 9677. Region 9678 redeveloped a magnetic delta structure in a penumbra in the trailing spots section. M class flares are possible. Region 9679 and 9681 decayed slowly and quietly. Region 9680 reemerged briefly with a couple of spots. Region 9682 decayed slowly and temporarily lost its magnetic delta structure. Major flares are still possible. Region 9683 decayed slowly and quietly. Region 9684 rotated fully into view and appears to be developing. M class flares are possible. Flares and CMEs A total of 7 C and 3 M class events were recorded on October 28. Region 9682 produced an M1.3/1F flare at 04:50, a C6.8/1F flare at 07:02, a C6.5 flare at 08:42, a C6.3 flare at 11:03, an M1.4/1N flare at 16:51 and a C3.7 flare at 17:06 UTC. An M1.5 flare at 10:00 UTC was optically unassigned. The background x-ray flux is at the class C1-C2 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to active on October 29 and quiet to unsettled on October 30-31. 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 Location region numbered no. at Area Classification Comment sunspots midnight 9670 2001.10.16 5 S18W80 0100 CAO 9672 2001.10.18 10 S18W67 0390 DKI beta-gamma-delta 9673 2001.10.18 1 N05W63 0080 HAX 9674 2001.10.19 S08W84 plage 9675 2001.10.20 S12W38 plage 9676 2001.10.20 1 N15W35 0030 HSX 9677 2001.10.21 3 N24W36 0000 AXX 9678 2001.10.23 34 N07W21 0620 EKI beta-gamma-delta 9679 2001.10.23 8 S09W07 0040 DAO 9680 2001.10.23 2 N22W07 0010 BXO now spotless 9681 2001.10.25 1 S24W37 0030 HSX 9682 2001.10.25 32 N12E32 0830 FKC beta-gamma-delta 9683 2001.10.26 2 N28E01 0010 BXO 9684 2001.10.27 10 N06E69 0510 DKI Total number of sunspots: 109 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) 2001.10 206.7 (1) 176.4 (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]