Solar Terrestrial Activity Report [Image] Last update January 21, 2001 at 03:55 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update January 2, 2001) - Has cycle 23 peaked?] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update January 2, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update January 2, 2001)] [Historical solar and geomagnetic data charts 1954-2000 (last update January 18, 2001)] Recent development The geomagnetic field was quiet to unsettled on January 20. Solar wind speed ranged between 297 and 331 km/sec. Solar flare activity was high. Solar flux was 153.2, the planetary A index was 8 (3-hour K indices: 0032 3233, Boulder K indices: 1142 1222). Region 9308 decayed and was quiet, the region rotated off the visible disk early on Jan.21. Region 9310 once again decayed into spotless plage. Region 9311 decayed slowly and was quiet. Region 9312 was quiet and stable, the region is spotless early on January 21. Region 9313 developed a magnetic delta feature inside the penumbra containing the trailing spots. Further M class flares are possible. Region 9315 decayed into spotless plage. Region 9316 was quiet and stable, C class flaring is possible. New region 9318 emerged in the southeast quadrant near the central meridian. An active region at a low latitude at the southeast limb will probably rotate into view today. Flares and CMEs A total of 5 C and 2 M class events were recorded on January 20. Region 9313 produced an M1.2/2F flare at 18:47 UT. The flare was accompanied by a strong type II sweep and a full halo coronal mass ejection. A major M7.7/2B flare was observed at 21:20 UT. This flare was accompanied by a moderate type II sweep and a large and fast coronal mass ejection. Although the main core of the CMEs will not be heading towards Earth, parts of the CMEs will begin to influence the geomagnetic field sometime between noon on January 22 and noon on January 23. The background x-ray flux is at the class B5 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to active on January 21 and most, if not all, of January 22. A CME based disturbance should start sometime on January 22 or 23 and could 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. 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 9308 2001.01.10 1 N17W82 0010 AXX 9310 2001.01.14 N27W28 plage 9311 2001.01.15 4 N05W20 0060 CSO 9312 2001.01.16 3 N06E07 0010 BXO 9313 2001.01.18 14 S07E42 0220 EAO beta-gamma-delta 9314 2001.01.18 N17W71 plage 9315 2001.01.19 S28E31 plage 9316 2001.01.19 7 S17E64 0200 DSO 9317 2001.01.19 N08W85 plage 9318 2001.01.20 2 S05E05 0020 DSO Total number of sunspots: 31 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) 2000.06 179.8 124.9 118.7 (-0.3) 2000.07 202.3 169.1 (120.3 predicted, +1.6) 2000.08 163.0 130.5 (120.8 predicted, +0.5) 2000.09 182.1 109.9 (119.9 predicted, -0.9) 2000.10 167.4 100.1 (118.7 predicted, -1.2) 2000.11 178.8 106.5 (116.8 predicted, -1.9) 2000.12 173.6 104.5 (114.2 predicted, -2.6) 2001.01 168.3 (1) 92.5 (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]