Solar Terrestrial Activity Report [Image] Last update December 10, 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 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 9. Solar wind speed ranged between 369 and 434 km/sec. Solar flare activity was low. Solar flux was 224.2, the planetary A index was 3 (3-hour K indices: 2001 1121, Boulder K indices: 0112 2102). Region 9717 rotated quietly off the visible disk. Region 9718 decayed and is rotating over the southwest limb. Region 9720 decayed and could become spotless today. Region 9721 decayed quietly. Region 9723 decayed slowly and quietly. Regions 9724 and 9726 were quiet and stable. Region 9727 changed in appearance but not much in spot count and area. M class flaring is possible. Region 9728 decayed quickly and is rotating out of view. Region 9731 decayed and could become spotless today. Region 9732 was quiet and stable. Region 9733 has a couple of dark filaments and has the potential to produce M class flares. New region 9734 rotated into view at the southeast limb. Flares and CMEs A total of 9 C class events were recorded on December 9. Region 9734 produced a C2.0 flare at 04:21 UTC. Region 9718 generated a C2.3 flare at 12:36 UTC. Region 9733 was the source of a C2.2 flare at 13:42, a C3.2 flare at 16:36, a C6.3 long duration event peaking at 18:02 and a C2.3 flare at 23:31 UTC. Region 9727 produced a C6.8/1F flare at 15:41 and a C4.5 flare at 20:34 UTC. The background x-ray flux is at the class C1 level. Coronal holes An extension of a large southern hemisphere coronal hole will rotate into a geoeffective position on December 11. Forecast The geomagnetic field is expected to be mostly quiet on December 10-12. There is a minor chance of a weak CME impact on December 10. 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 9717 2001.11.27 1 N05W88 0070 HSX 9718 2001.11.27 10 S06W76 0280 DAO 9720 2001.11.28 9 S28W63 0040 DSO 9721 2001.11.28 3 N11W64 0110 DAO 9723 2001.12.01 3 S05W68 0040 CSO 9724 2001.12.01 1 N10W33 0030 HSX 9726 2001.12.02 8 S16W22 0040 DSO 9727 2001.12.03 23 S20W10 0360 DAI beta-gamma-delta 9728 2001.12.04 5 N35W71 0050 ESO 9729 2001.12.05 N23W48 plage 9730 2001.12.05 S12W05 plage 9731 2001.12.06 5 N25W04 0010 BXO 9732 2001.12.07 4 N04E36 0060 CSO 9733 2001.12.08 21 N14E58 0290 EAI beta-gamma 9734 2001.12.09 2 S12E81 0050 CAO Total number of sunspots: 95 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) 2001.12 232.1 (1) 66.2 (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]