Solar Terrestrial Activity Report [Image] Last update February 6, 2001 at 04:30 UT. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update February 2, 2001) - Cycle 23 peaked in April 2000?] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update February 2, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update February 2, 2001)] [Historical solar and geomagnetic data charts 1954-2000 (last update January 18, 2001)] Recent development The geomagnetic field was quiet on February 5. Solar wind speed ranged between 279 and 352 km/sec. A coronal stream began to influence the interplanetary magnetic field at ACE just before midnight. A disturbance was in progress at approximately 03 UT on February 6. Solar flare activity was low. Solar flux was 165.3, the planetary A index was 3 (3-hour K indices: 0000 1122, Boulder K indices: 0001 1211). Regions 9327 and 9333 were mostly quiet and stable, both regions are spotless early on Feb.6. Region 9330 decayed slowly and could produce C class flares. Region 9334 decayed slightly and is capable of producing C and minor M class flares. Region 9335 was unstable and could generate minor M class flares. Region 9336 was quiet and stable, no spots were visible early in the day, after noon several spots emerged and further minor development is possible. Region 9337 was quiet and stable, as was region 9338. Region 9339 developed slowly and could produce minor M class flares. New region 9340 emerged in the southeast quadrant near the central meridian, the region is spotless early on Feb.6. Flares and CMEs A total of 3 C class events were recorded on February 5. Region 9335 produced a C8.2/1F flare 15:20 UT. This event was accompanied by a weak type II sweep and possibly a weak full halo CME. A C1.2 flare at 23:21 UT triggered a filament eruption just north of region 9335. Region 9327 generated a C1.9 flare at 16:52 UT. 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 February 6-7 under the influence of a coronal stream. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair but will likely deteriorate to poor by the end of the day. 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 9325 2001.01.25 N11W87 plage 9327 2001.01.27 1 N19W73 0010 HRX 9329 2001.01.29 S09W40 plage 9330 2001.01.30 6 N26W09 0090 DAO 9331 2001.01.30 N13W52 plage 9332 2001.01.30 N09W58 plage 9333 2001.02.01 1 N26W64 0010 AXX 9334 2001.02.01 17 N12E27 0180 EAI 9335 2001.02.03 11 N08E40 0080 DAO 9336 2001.02.03 4 S09W27 0010 CRO 9337 2001.02.03 4 S28E51 0020 CRO 9338 2001.02.04 2 S18E50 0020 BXO 9339 2001.02.04 7 S11E62 0220 EAO beta-gamma 9340 2001.02.05 4 S13E05 0010 BXO Total number of sunspots: 57 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) 2000.02 174.1 112.9 116.8 (+3.9) 2000.03 208.2 138.5 119.9 (+3.1) 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) 2000.07 202.3 170.1 119.8 (+1.1) 2000.08 163.0 130.5 (119.7 predicted, -0.1) 2000.09 182.1 109.7 (118.4 predicted, -1.3) 2000.10 167.4 100.1 (116.7 predicted, -1.7) 2000.11 178.8 106.5 (114.8 predicted, -1.9) 2000.12 173.6 104.5 (112.2 predicted, -2.6) 2001.01 166.6 95.7 (108.7 predicted, -3.5) 2001.01 160.8 (1) 25.7 (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]