Solar Terrestrial Activity Report [Image] Last update December 29, 2000 at 04:20 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 28. Solar wind speed ranged between 337 and 421 km/sec. Solar flare activity was low. Solar flux was 185.4, the planetary A index was 5 (3-hour K indices: 2112 3110, Boulder K indices: 1222 1211). Region 9279 was quiet and stable, the region is rotating over the west limb. Region 9280 was mostly quiet and stable, the region appears to have decayed quickly late in the day and has less than 10 spots early on Dec.29. Region 9282 decayed slowly and was quiet. Region 9283 decayed slowly and was mostly quiet. A minor M class flare is possible. Region 9285 decayed slowly and was quiet. Regions 9287 and 9288 decayed into spotless plage. Region 9289 developed quickly and is now a large region capable of producing major flares. A weak magnetic delta configuration is evident in the very large penumbra containing the leader spots. Region 9290 developed slowly and could produce C class flares. Flares and CMEs A total of 10 C class events were recorded on December 28. Region 9289 produced a C3.5 flare at 02:19, a C4.5 flare at 02:49, a C5.1/1F flare at 04:17 and a C2.7/1F flare at 13:26 UTC. Region 9279 generated a C2.3 flare at 14:29 UTC while region 9283 managed a C1.3 flare at 18:26 UTC. A bright full halo CME was observed starting at 12:30 UTC in LASCO C2 images. The source of the event was on the backside of the sun. Region 9289 produced an M1.2 flare at 02:23 UTC on December 29. This flare was superimposed on a long duration C9 event occurring in region 9283. The background x-ray flux is at the class B7 level. Coronal holes A coronal hole (mainly) in the northern hemisphere will rotate into a geoeffective position on January 2-4. Forecast The geomagnetic field is expected to be quiet to unsettled on December 29-30, possibly with a few active intervals on Dec.29. 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 Location region numbered no. at Area Classification Comment sunspots midnight 9278 2000.12.17 N10W83 plage 9279 2000.12.18 1 S12W77 0090 HSX 9280 2000.12.19 24 N08W45 0330 EAI 9281 2000.12.20 N07W66 plage 9282 2000.12.21 1 N20W22 0020 HSX 9283 2000.12.22 23 S11W03 0180 EAI beta-gamma 9284 2000.12.23 N06W72 plage 9285 2000.12.24 6 N07E06 0020 BXO 9287 2000.12.25 S16E17 plage 9288 2000.12.26 S21E00 plage 9289 2000.12.26 20 S06E57 0790 EKO beta-gamma-delta 9290 2000.12.27 14 N30E19 0060 CAO Total number of sunspots: 89 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) 2000.12 173.2 (1) 131.3 (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]