Solar Terrestrial Activity Report [Image] Last update October 3, 2001 at 03:20 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 active to major storm on October 2. Solar wind speed ranged between 457 and 572 km/sec. Solar flare activity was moderate. Solar flux was 200.9, the planetary A index was 43 (3-hour K indices: 4565 4555, Boulder K indices: 3564 3444). Region 9632 rotated off the visible disk but could still produce an M class flare from just behind the southwest limb. Region 9633 was quiet and stable. Region 9634 decayed and was mostly quiet. Region 9636 decayed slowly and remains capable of minor M class flare production. Region 9637 decayed further and was quiet. Region 9639 decayed quietly, as did regions 9640 and 9642. Region 9641 developed until it produced an M flare, then began to decay slowly. Region 9643 was spotless all day in all available images. Regions 9644 and 9645 were quiet and stable. Region 9646 decayed and could become spotless today. New region 9647 emerged briefly in the southeast quadrant, it is spotless early on October 3. New region 9648 rotated into view at the southeast limb. It will likely be followed today by the appearance of old region 9608 at the southeast limb. Flares and CMEs A total of 6 C and 2 M class events were observed on October 2. An optically unaccounted M1.4 long duration event was recorded peaking at 10:21 UTC. Region 9641 produced an M1.0 flare at 11:27 UTC. Region 9634 generated a C3.8 flare at 15:49 UTC. October 1: Region 9628 seems to have been the source of a major M9.1 flare peaking at 05:15 UTC. Flux levels then dropped towards the M1 level before increasing slowly to the M2.4 level around 08h UTC. A large and wide full halo CME was produced and the CME could have geoeffective extensions. 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 minor storm on October 3 and quiet to active on October 4. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor to useless. 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 9632 2001.09.20 6 S21W88 0220 EKI beta-gamma 9633 2001.09.22 3 N21W56 0080 HSX 9634 2001.09.22 4 N12W51 0050 HSX 9636 2001.09.24 18 N14W41 0250 EAC beta-gamma 9637 2001.09.24 9 S14W35 0090 DAO 9638 2001.09.25 N03W30 plage 9639 2001.09.26 2 N03W51 0040 HSX 9640 2001.09.27 10 N10E00 0020 CAO 9641 2001.09.27 11 S14E08 0250 DAO 9642 2001.09.29 1 N05E28 0040 HSX 9643 2001.10.01 1 S27W37 0000 AXX 9644 2001.10.01 7 N19W17 0030 CSO 9645 2001.10.01 10 S18W12 0030 DSO 9646 2001.10.01 2 N12E28 0010 BXO 9647 2001.10.02 1 S16E31 0000 AXX 9648 2001.10.02 1 S04E78 0050 HSX Total number of sunspots: 86 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 2000.08 163.0 130.5 118.6 (-1.1) 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) 2001.10 208.7 (1) 16.9 (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]