Solar Terrestrial Activity Report [Image] Last update February 2, 2001 at 03:50 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 1. Solar wind speed ranged between 385 and 439 km/sec. Solar flare activity was low. Solar flux was 160.9, the planetary A index was 7 (3-hour K indices: 1332 2112, Boulder K indices: 1331 2222). Region 9321 decayed slowly and was quiet, the region has rotated off the visible disk. Region 9325 was quiet and stable. Region 9327 decayed fairly quickly and has only a couple of spots left early on February 2. Region 9329 decayed and was quiet, the region is spotless early on February 2. Region 9330 was mostly unchanged and could produce minor M class flares. Region 9331 was quiet and stable, the region is spotless early on February 2. Region 9332 was quiet and stable. New region 9333 emerged in the northwest quadrant near the central meridian. New region 9334 rotated partly into view at the northeast limb. Flares and CMEs A total of 5 C class events were recorded on February 1. Region 9330 produced a C7.9 flare at 07:12, a C2.6 flare at 13:00 and a C4.1 flare at 17:12 UT. The background x-ray flux is at the class B7 level. Coronal holes An isolated coronal hole in the northern hemisphere could move into a geoeffective position on February 3-5. Forecast The geomagnetic field is expected to be quiet to unsettled on February 2-3. 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 9321 2001.01.21 6 S04W81 0110 DAO 9324 2001.01.23 N10W76 plage 9325 2001.01.25 3 N10W32 0030 CAO 9327 2001.01.27 11 N18W21 0050 DAO 9329 2001.01.29 2 S11E06 0010 BXO 9330 2001.01.30 12 N25E44 0220 EAO 9331 2001.01.30 3 N13E00 0010 BXO 9332 2001.01.30 8 N08W03 0040 DSO 9333 2001.02.01 5 N24W10 0020 CSO 9334 2001.02.01 1 N12E78 0060 HSX Total number of sunspots: 51 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) 2001.01 160.9 (1) 5.0 (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]