Solar Terrestrial Activity Report [Image] Last update December 9, 2000 at 04:35 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 quiet to active on December 8. Solar wind speed ranged between 477 and 665 km/sec under the influence of a fairly benign high speed coronal stream. Solar flare activity was low. Solar flux was 138.3, the planetary A index was 17 (3-hour K indices: 4433 4432, Boulder K indices: 4332 4433). Region 9246 rotated off the visible disk. Region 9249 once again decayed into spotless plage. Region 9254 was mostly unchanged and quiet, C class flares are possible. Region 9255 decayed into spotless plage. Region 9257 was quiet and stable. Region 9258 decayed into spotless plage. Regions 9259 and 9260 developed slowly and were quiet. Region 9261 decayed into spotless plage. New region 9262 rotated into view at the northeast limb. Another region at the northeast limb could rotate into view today. Flares and CMEs A total of 8 C class events were recorded on December 8, none of the flares were optically correlated to regions on the visible disk. LASCO EIT images suggest at least 3 or 4 of the flares had their origin just behind the northwest limb. The background x-ray flux is at the class B6 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 9-10, isolated minor storm intervals are possible. 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 N04W65 plage 9246 20001128 1 S11W94 0000 AXX 9249 20001130 N09W61 plage 9253 20001203 S14W54 plage 9254 20001203 10 N11W04 0120 DAO 9255 20001203 N23E01 plage 9256 20001204 S17E11 plage 9257 20001206 1 N20E09 0000 AXX 9258 20001207 N14E35 plage 9259 20001207 3 S09W35 0020 BXO 9260 20001207 4 S05W59 0040 CSO 9261 20001207 N05W82 plage 9262 20001208 2 N13E70 0010 BXO Total number of sunspots: 21 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) 2000.12 154.6 (1) 32.2 (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]