Solar Terrestrial Activity Report [Image] Last update December 8, 2000 at 01:35 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 7. Solar wind speed ranged between 363 and 451 km/sec. A weak disturbance was in progress all day. Solar flare activity was low. Solar flux was 144.2, the planetary A index was 13 (3-hour K indices: 2333 4323, Boulder K indices: 2334 3222). Region 9245 decayed into spotless plage. Region 9246 developed slowly and could produce a minor M class flare before departing the visible disk late today and early tomorrow. Region 9249 reemerged with a single spot. Region 9254 was mostly unchanged and will likely continue to produce C flares. Region 9255 was quiet and stable. Region 9256 decayed into spotless plage. Region 9257 was quiet and stable. New region 9258 emerged in the northeast quadrant. New regions 9259 and 9260 emerged in the southwest quadrant. New region 9261 emerged in the northwest quadrant. Flares and CMEs A total of 8 C class events were recorded on December 7. Region 9246 produced a C5.4 flare at 01:15, a C1.7/1F flare at 03:40, a C2.1 flare at 06:00 and a C1.0 flare at 06:45 UTC. A long duration C5.4 event peaked at 19:40 UTC and had its origin just behind the northwest limb. The background x-ray flux is at the class B8 level. Coronal holes A large trans equatorial coronal hole was in a geoeffective position on December 6-8 and will cause unsettled to major storm conditions on December 9-12. Forecast The geomagnetic field is expected to be quiet to active on December 8. Unsettled to minor storm is expected on December 9 due to a coronal stream, isolated major 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 N04W52 plage 9246 20001128 7 S11W75 0250 EAO 9247 20001129 N14W85 plage 9249 20001130 1 N09W48 0000 AXX 9251 20001203 S22W86 plage 9252 20001203 S02W88 plage 9253 20001203 S14W41 plage 9254 20001203 10 N10E10 0160 DAO 9255 20001203 1 N23E14 0000 AXX 9256 20001204 S17E24 plage 9257 20001206 4 N19E24 0010 BXO 9258 20001207 2 N14E48 0010 BXO 9259 20001207 4 S10W24 0010 BXO 9260 20001207 4 S04W47 0010 BXO 9261 20001207 2 N05W69 0010 BXO Total number of sunspots: 35 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) 2000.04 184.2 125.5 120.8 (+0.9) 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) 2000.12 156.9 (1) 29.6 (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]