Solar Terrestrial Activity Report [Image] Last update October 7, 2001 at 06:10 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 July 27, 2001)] Recent development The geomagnetic field was quiet to unsettled on October 6. Solar wind speed ranged between 366 and 435 km/sec. Solar flare activity was moderate. Solar flux was 180.4, the planetary A index was 8 (3-hour K indices: 2222 3222, Boulder K indices: 2222 3211). Region 9636 rotated off the visible disk. Region 9637 rotated quietly over the southwest limb. Region 9641 decayed quietly. Region 9642 was quiet and stable. Region 9645 decayed slowly and is approaching the southwest limb. Region 9648 was mostly quiet and stable. Region 9650 developed slowly and could produce C class flares. Region 9651 decayed further and could become spotless today. Region 9652 was quiet and stable. Region 9653 did not change much and was quiet. Region 9654 decayed and was spotless by early evening. New region 9655 rotated into view at the southeast limb. Flares and CMEs A total of 2 C and 1 M class events were observed on October 6. Region 9650 produced a C2.6 flare at 10:43 UTC. Region 9648 was the source of a C3.6/1F flare at 17:33 UTC. A long duration M2.8 event peaked at 05:27 UTC, its source was at the northwest limb near region 9636. The background x-ray flux is at the class B7 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on October 7-8. 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 region numbered sunspots at Area Classification Comment midnight 9636 2001.09.24 1 N13W94 0090 HSX 9637 2001.09.24 1 S13W89 0030 HSX 9638 2001.09.25 N03W82 plage 9640 2001.09.27 N11W53 plage 9641 2001.09.27 3 S13W48 0100 HAX 9642 2001.09.29 1 N05W27 0010 HSX 9643 2001.10.01 S27W89 plage 9644 2001.10.01 N20W68 plage 9645 2001.10.01 10 S18W68 0180 EAO 9646 2001.10.01 N13W28 plage 9647 2001.10.02 S18W21 plage 9648 2001.10.02 5 S07E22 0080 CAO 9650 2001.10.03 18 S15E31 0130 DAO 9651 2001.10.04 5 S24W39 0010 BXO 9652 2001.10.04 7 N21W13 0020 BXO 9653 2001.10.04 5 S22E50 0270 DKO 9654 2001.10.05 3 N07W06 0010 BXO now spotless 9655 2001.10.06 2 S22E64 0180 HKX Total number of sunspots: 61 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. 2000.07 202.3 170.1 119.7 2000.09 182.1 109.7 116.3 (-2.3) 2000.10 167.4 99.4 114.5 (-1.8) 2000.11 178.8 106.8 112.8 (-1.7) 2000.12 173.6 104.4 112.1 (-0.7) 2001.01 166.6 95.6 108.8 (-3.3) 2001.02 146.6 80.6 104.1 (-4.7) 2001.03 177.7 113.5 104.8 (+0.7) 2001.04 177.7 108.2 (107.7 predicted, +2.9) 2001.05 147.1 97.3 (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) 2001.10 192.2 (1) 41.7 (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] [StudyWeb]