Solar Terrestrial Activity Report [Image] Last update December 28, 2000 at 04:45 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 quiet to unsettled on December 27. Solar wind speed ranged between 357 and 449 km/sec. Solar flare activity was moderate. Solar flux was 187.6, the planetary A index was 7 (3-hour K indices: 1111 3331, Boulder K indices: 2111 3322). Region 9279 was quiet and stable. Region 9280 decayed slowly and was quiet. Region 9282 was quiet and stable. Region 9283 did not change significantly and remains capable of producing a major flare. Region 9285 decayed slowly and was quiet. Region 9287 was quiet and stable, as was region 9288. Both regions could become spotless within a couple of days. Region 9289 has a large penumbra containing the leader spots. The region is very active and could produce further M class flares, even major ones. New region 9290 emerged in the northeast quadrant. Flares and CMEs A total of 19 C and 1 M class events were recorded on December 27. Region 9283 produced a C1.1 flare at 04:16, a C2.4 flare at 05:31, a C5.4 flare at 10:56 and a C1.5 flare at 17:53 UTC. Region 9289 was the source of an M1.3 flare at 16:13 UTC. The background x-ray flux is at the class B7 level. Coronal holes A coronal hole is rotating into view at the east limb and should reach a geoeffective position on January 2. Forecast The geomagnetic field is expected to be quiet to unsettled on December 28-30. 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 9273 2000.12.15 N20W85 plage 9278 2000.12.17 N10W70 plage 9279 2000.12.18 1 S10W64 0080 HSX 9280 2000.12.19 25 N10W31 0290 EAI 9281 2000.12.20 N07W53 plage 9282 2000.12.21 1 N21W09 0030 HSX 9283 2000.12.22 21 S11E11 0240 DAO beta-gamma 9284 2000.12.23 N06W59 plage 9285 2000.12.24 12 N08E20 0040 CSO 9286 2000.12.24 N31W88 plage 9287 2000.12.25 1 S16E30 0000 AXX 9288 2000.12.26 2 S21E13 0000 AXX 9289 2000.12.26 12 S08E64 0330 DAO beta-gamma 9290 2000.12.27 6 N30E31 0040 CSO 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) 2000.12 172.7 (1) 126.2 (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]