Solar Terrestrial Activity Report [Image] Last update December 10, 2000 at 05:45 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, 2000) - Has cycle 23 peaked?] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update December 2, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update December 2, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update October 20, 2000)] Recent development The geomagnetic field was unsettled to active on December 9. Solar wind speed ranged between 587 and 698 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 134.7, the planetary A index was 16 (3-hour K indices: 3433 3334, Boulder K indices: 3433 3323). Region 9254 was mostly unchanged and quiet, C class flares are possible. Region 9257 was quiet and stable, the region could become spotless today. Region 9259 decayed into spotless plage. Region 9260 was quiet and stable and will rotate off the visible disk on December 11. Region 9262 developed slowly and could produce C class flares. New region 9263 rotated into view at the northeast limb. An active region is rotating into view at the southeast limb. Flares and CMEs A total of 4 C class events were recorded on December 9, all flares were optically uncorrelated. The background x-ray flux is at the class B4 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to active on December 10-11. 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 at region numbered sunspots midnight Area Classification Comment 9245 20001128 N04W78 plage 9249 20001130 N09W74 plage 9253 20001203 S14W67 plage 9254 20001203 14 N10W19 0080 DAO 9255 20001203 N23W12 plage 9256 20001204 S17W02 plage 9257 20001206 3 N19W03 0020 CRO 9258 20001207 N14E22 plage 9259 20001207 S09W48 plage 9260 20001207 1 S05W71 0030 HSX 9262 20001208 4 N14E58 0110 DAO 9263 20001209 1 N18E67 0010 HRX Total number of sunspots: 23 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.11 191.5 133.2 111.0 (+3.2) 1999.12 169.8 84.6 111.1 (+0.1) 2000.01 158.1 90.1 112.9 (+1.8) 2000.02 174.1 112.9 116.7 (+3.8) 2000.03 208.2 138.5 119.9 (+3.2) 120.8 (+0.9) 2000.04 184.2 125.5 cycle 23 peak candidate 2000.05 184.9 121.6 119.0 (-1.8) 2000.06 179.8 124.9 (118.3 predicted, -0.7) 2000.07 202.3 169.1 (119.8 predicted, +1.5) 2000.08 163.0 130.5 (120.5 predicted, +0.7) 2000.09 182.1 109.9 (119.6 predicted, -0.9) 2000.10 167.4 100.1 (118.4 predicted, -1.2) 2000.11 178.8 106.5 (116.4 predicted, -2.0) 2000.12 152.4 (1) 34.6 (2) 1) Running average based on the daily 20:00 UTC solar flux value at 2800 MHz. 2) Unofficial, accumulated value. The official value 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]