Solar Terrestrial Activity Report [Image] Last update December 11, 2001 at 04:40 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update December 2, 2001)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update December 2, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update December 2, 2001)] [Historical solar and geomagnetic data charts 1954-2001 (last update October 16, 2001)] Recent development The geomagnetic field was quiet on December 10. Solar wind speed ranged between 346 and 382 km/sec. Solar flare activity was low. Solar flux was 219.0, the planetary A index was 4 (3-hour K indices: 1121 2211, Boulder K indices: 0021 2211). Region 9718 rotated quietly off the visible disk. Region 9720 decayed was spotless late in the day. Region 9721 decayed quietly and is rotating over the northwest limb. Region 9723 decayed and is rotating out of view. Region 9724 was quiet and stable. Region 9726 decayed and could become spotless today. Region 9727 developed a stronger magnetic delta structure and increased its areal coverage. M class flares are likely and there is a possibility of a proton flare. Region 9728 rotated quietly over the northwest limb. Region 9732 decayed slowly and quietly. Region 9733 developed fairly quickly and has a magnetic delta structure in a trailing penumbra. M class flares are possible. Region 9734 was quiet and stable. New region 9735 emerged in the northwest quadrant. New region 9736 emerged in the southwest quadrant. New region 9737 emerged in the southeast quadrant. Flares and CMEs A total of 7 C class events were recorded on December 10. Region 9727 produced a C8.6 flare at 09:38 (with an accompanying strong type II radio sweep), a C2.3 flare at 12:24 and a C4.2 flare at 17:52 UTC. Region 9733 generated a C7.0/1F long duration event peaking at 22:44 UTC. The background x-ray flux is at the class C1 level. Coronal holes An extension of a large southern hemisphere coronal hole well be in a geoeffective position on December 10-12. Forecast The geomagnetic field is expected to be mostly quiet on December 11-12. A coronal stream should begin to influence the field on December 13 and cause unsettled to active conditions, perhaps with isolated minor storm intervals on December 14. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to good. 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 9718 2001.11.27 3 S06W89 0200 DAO 9720 2001.11.28 1 S28W73 0010 HSX 9721 2001.11.28 2 N11W79 0100 DSO 9723 2001.12.01 1 S05W81 0010 HSX 9724 2001.12.01 1 N10W48 0030 HSX 9726 2001.12.02 6 S16W37 0020 DRO 9727 2001.12.03 31 S21W24 0550 DKC beta-gamma-delta 9728 2001.12.04 1 N35W90 0020 HSX 9729 2001.12.05 N23W61 plage 9730 2001.12.05 S12W18 plage 9731 2001.12.06 N25W17 plage 9732 2001.12.07 2 N04E20 0040 HSX 9733 2001.12.08 27 N14E44 0360 EAI beta-gamma-delta 9734 2001.12.09 1 S12E65 0030 HSX 9735 2001.12.10 2 N10W34 0020 BXO 9736 2001.12.10 3 S09W27 0010 BXO 9737 2001.12.10 3 S27E52 0010 BXO Total number of sunspots: 84 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 2000.10 167.4 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) 2001.04 177.7 107.7 107.6 (+2.8) 2001.05 147.1 96.6 108.7 (+1.1) 2001.06 173.0 134.0 (108.5 predicted, -0.2) 2001.07 131.3 82.2 (108.1 predicted, -0.4) 2001.08 162.9 106.8 (108.7 predicted, +0.6) 2001.09 233.2 150.7 (108.1 predicted, -0.6) 2001.10 207.6 125.6 (105.3 predicted, -2.8) 2001.11 210.6 106.5 (103.7 predicted, -1.6) 2001.12 230.8 (1) 73.4 (2) (100.3 predicted, -3.4) 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]