Solar Terrestrial Activity Report [Image] Last update February 3, 2001 at 05:30 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 to unsettled on February 2. Solar wind speed ranged between 362 and 438 km/sec. Solar flare activity was moderate. Solar flux was 166.3, the planetary A index was 5 (3-hour K indices: 3202 1221, Boulder K indices: 3112 2232). Region 9325 was quiet and stable, as were regions 9327 and 9329. Region 9330 was mostly unchanged and could produce minor M class flares. Regions 9332 and 9333 were quiet and stable. Region 9334 rotated fully into view and may be capable of further M class flaring. The region may actually consist of two separate regions, at least that's what's indicated by recent magnetograms. Flares and CMEs A total of 3 C and 1 M class events were recorded on February 2. Region 9334 produced an M2.4 flare at 00:06 UT. An accompanying CME was observed off the east limb. A long duration event, a filament eruption, began in the northeast quadrant between regions 9334 and 9330 at 19:48 UT and caused a minor CME which was observed above the northeast limb. Another filament eruption, this time in the northwest quadrant just northwest of region 9325, began at 07:13 UT and caused a long duration C2.4 event which peaked at 09:18 UT. A coronal mass ejection was observed above the northwest limb. The background x-ray flux is at the class B7 level. Coronal holes An isolated coronal hole in the northern hemisphere will be in a geoeffective position on February 3-4. Forecast The geomagnetic field is expected to be quiet to unsettled on February 3-5. A coronal stream is expected to influence the field from February 6 and could cause unsettled to active conditions. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor. 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 9324 2001.01.23 N10W89 plage 9325 2001.01.25 1 N10W48 0010 HSX 9327 2001.01.27 4 N17W36 0030 DSO 9329 2001.01.29 2 S10W06 0010 AXX 9330 2001.01.30 16 N26E31 0140 EAO 9331 2001.01.30 N13W13 plage 9332 2001.01.30 5 N08W19 0030 DAO 9333 2001.02.01 5 N25W24 0030 DAO 9334 2001.02.01 6 N11E67 0200 ESO Total number of sunspots: 39 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) 2001.01 163.6 (1) 8.9 (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]