Solar Terrestrial Activity Report [Image] Last update December 31, 2000 at 06:35 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 on December 30. Solar wind speed ranged between 329 and 374 km/sec. Solar flare activity was low. Solar flux was 182.1, the planetary A index was 2 (3-hour K indices: 1001 1111, Boulder K indices: 1102 2221). Region 9280 decayed slowly and was quiet. Region 9282 decayed slowly and could become spotless today or tomorrow. Region 9283 decayed slowly and could produce occasional C flares. Region 9285 was quiet and stable, the region could become spotless today or tomorrow. Region 9289 developed slowly with both spot number and areal coverage increasing. The positive and negative polarity areas drifted apart and the region is not as complex as it has been. M class flares are still possible. Region 9290 lost some of its spots and was quiet. Region 9291 was quiet and stable. New region 9292 rotated into view at the northeast limb but seems to be decaying quickly. Another active region is rotating into view at the northeast limb. Flares and CMEs A total of 6 C class events were recorded on December 30. Region 9283 produced a C5.4 flare at 10:39 UTC. Region 9289 generated a C2.1 flare at 14:58 UTC. December 29: Region 9283 produced a long duration C9.0/1F event peaking at 02:35 UTC. A filament eruption was observed starting at 01:13 UTC in LASCO EIT images. This eruption occurred near the central meridian and is likely to have produced a geoeffective CME. The background x-ray flux is at the class B5 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 on December 31. A CME could arrive on January 1 and cause unsettled to minor storm conditions. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to good. 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 9280 2000.12.19 5 N09W70 0150 EAO 9282 2000.12.21 1 N22W47 0010 HSX 9283 2000.12.22 10 S11W28 0100 DAO 9285 2000.12.24 4 N07W19 0020 CSO 9287 2000.12.25 S16W09 plage 9288 2000.12.26 S21W26 plage 9289 2000.12.26 24 S07E30 0890 EKI beta-gamma 9290 2000.12.27 8 N30W06 0070 DSO 9291 2000.12.29 7 S12E21 0070 CAO 9292 2000.12.30 1 N25E63 0060 HSX Total number of sunspots: 60 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) 2000.12 173.7 (1) 140.7 (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]