Solar Terrestrial Activity Report [Image] Last update December 16, 2000 at 05:25 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 on December 15. Solar wind speed ranged between 323 and 391 km/sec. Solar flare activity was low. Solar flux was 187.8, the planetary A index was 3 (3-hour K indices: 0001 2211, Boulder K indices: 0001 2201). Region 9262 decayed further losing most spots during the day. A new region emerged to the north of region 9262. SEC/NOAA apparently decided that this new region was part of region 9262. Region 9264 was mostly unchanged, C and minor M class flares are possible. Region 9265 was quiet and stable, the region is spotless early on Dec.16. Region 9266 developed further and could produce C flares. Region 9267 was mostly quiet and stable. Region 9268 was quiet and stable. Region 9269 developed slowly and could produce C flares and perhaps a minor M class flare. Regions 9271 and 9272 were quiet and stable. New region 9273 rotated into view at the northeast limb. Flares and CMEs A total of 5 C class events were recorded on December 15. Region 9267 produced a C2.7 flare at 11:19 UTC. Region 9269 generated a C1.3 flare at 18:59. Region 9262 was the source of a C5.3 flare at 19:56 UTC, while region 9264 managed a C2.5 flare at 21:29 UTC. Region 9266 produced a C1.1 flare at 06:51 UTC. The background x-ray flux is at the class B6 level. Coronal holes A small coronal hole in the northern hemisphere was in a geoeffective position on December 13. Forecast The geomagnetic field is expected to be quiet to unsettled on December 16-17. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair. 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 9256 2000.12.04 S17W80 plage 9257 2000.12.06 N18W85 plage 9258 2000.12.07 N14W56 plage 9262 2000.12.08 12 N16W20 0050 CSO 9263 2000.12.09 N18W14 plage 9264 2000.12.10 18 S24E04 0250 EAI 9265 2000.12.10 9 N16E04 0010 BXO 9266 2000.12.11 5 N23W62 0070 DRO 9267 2000.12.11 14 N07W17 0210 DAI 9268 2000.12.13 1 S18E49 0100 HSX 9269 2000.12.13 9 N15E36 0120 CAO 9270 2000.12.13 S10W16 plage 9271 2000.12.14 5 S19W41 0030 BXO 9272 2000.12.14 5 N14E05 0030 BXO 9273 2000.12.15 3 N20E68 0120 DAO Total number of sunspots: 81 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) 2000.12 156.4 (1) 59.3 (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]