Solar Terrestrial Activity Report [Image] Last update January 31, 2001 at 04:35 UT. [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 30. Solar wind speed ranged between 383 and 467 km/sec. Solar flare activity was low. Solar flux was 159.6, the planetary A index was 4 (3-hour K indices: 1300 1111, Boulder K indices: 2300 0100). Region 9321 decayed slowly and was quiet. The region could produce a minor M class flare. Region 9325 decayed slowly and was quiet. Region 9327 developed fairly quickly and could produce C flares. Region 9328 was quiet and stable, the region has rotated off the visible disk. Region 9329 was quiet and stable. New region 9330 rotated partly into view at the northeast limb and could produce at least C class flares. New regions 9331 and 9332 emerged in the northeast quadrant. Flares and CMEs A total of 4 C class events were recorded on January 30. Region 9330 was the source of a C2.0 flare at 18:53 UT. January 29: Region 9329 produced a C5.7 flare at 15:40 UT. A filament eruption was triggered to the north of the region and was observed in LASCO-EIT images from 15:48 UT. A partial halo CME could be seen in LASCO C3 images, this CME has a chance of reaching Earth on February 1 or 2. January 28: Region 9313 was the source of a long duration M1.5/1N event peaking at 16:00 UT. A wide full halo CME was observed and the CME will likely reach Earth sometime between late on January 30 and noon on January 31. The background x-ray flux is at the class B6 level. Coronal holes An isolated coronal hole in the northern hemisphere could move into a geoeffective position on February 3. Forecast The geomagnetic field is expected to be quiet to minor storm on January 31 and quiet to active on February 1. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to 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 9316 2001.01.19 S15W71 plage 9321 2001.01.21 20 S06W51 0150 EAI 9323 2001.01.23 S29W86 plage 9324 2001.01.23 N10W50 plage 9325 2001.01.25 4 N10W04 0030 CSO 9326 2001.01.26 N26W81 plage 9327 2001.01.27 9 N18E06 0050 DAO 9328 2001.01.28 3 N06W87 0050 HAX 9329 2001.01.29 5 S10E36 0020 CSO 9330 2001.01.30 1 N24E67 0100 HSX 9331 2001.01.30 3 N13E27 0050 DAO 9332 2001.01.30 3 N08E24 0020 CSO Total number of sunspots: 48 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) 2001.01 167.1 (1) 138.5 (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]