Solar Terrestrial Activity Report [Image] Last update October 5, 2001 at 03:40 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update 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 minor storm on October 4. Solar wind speed ranged between 407 and 569 km/sec. Solar flare activity was low. Solar flux was 186.5, the planetary A index was 19 (3-hour K indices: 4154 3432, Boulder K indices: 4144 4421). Region 9633 was quiet and stable and is rotating off the visible disk. Region 9634 did not change much and was quiet, the region will rotate over the northwest limb late today. Region 9636 decayed further and was mostly quiet, the region will rotate off the visible disk tomorrow. Region 9637 decayed further and was quiet. Region 9639 decayed and is rotating off the visible disk. Region 9640 decayed and was spotless by late evening. Region 9641 decayed slowly and quietly. Region 9642 was quiet and stable. Region 9644 decayed and was spotless by early evening. Region 9645 developed early in the day, then decayed slowly. Region 9646 decayed and was spotless by early evening. Region 9648 was quiet and stable, as were regions 9649 and 9650. New region 9651 emerged in the southwest quadrant. New region 9652 emerged in the northeast quadrant. The region appeared to be decaying late in the day and could become spotless today. New region 9653 rotated into view at the southeast limb. Flares and CMEs A total of 7 C class events were observed on October 4. Region 9636 produced a C2.6 flare at 03:12 UTC. Region 9645 generated a C2.7 flare at 06:11 and a C2.3 flare at 06:34 UTC. 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 unsettled on October 5-6. 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 no. Location region numbered sunspots at Area Classification Comment midnight 9633 2001.09.22 1 N23W82 0060 HSX 9634 2001.09.22 4 N12W76 0110 CAO 9636 2001.09.24 7 N13W70 0150 DSO beta-gamma 9637 2001.09.24 5 S14W62 0060 CAO 9638 2001.09.25 N03W56 plage 9639 2001.09.26 1 N07W77 0010 AXX 9640 2001.09.27 5 N11W27 0020 BXO now spotless 9641 2001.09.27 7 S13W19 0140 CSO 9642 2001.09.29 1 N05E02 0030 HSX 9643 2001.10.01 S27W63 plage 9644 2001.10.01 1 N20W42 0010 AXX now spotless 9645 2001.10.01 9 S17W41 0150 DSO 9646 2001.10.01 3 N13W02 0010 BXO now spotless 9647 2001.10.02 S16E05 plage 9648 2001.10.02 1 S06E49 0110 HSX 9649 2001.10.03 1 S08E56 0040 HSX 9650 2001.10.03 7 S15E54 0040 CSO 9651 2001.10.04 5 S22W12 0030 CSO 9652 2001.10.04 2 N22E14 0010 BXO 9653 2001.10.04 1 S23E76 0060 HAX 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) 2001.10 198.9 (1) 30.7 (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]