Solar Terrestrial Activity Report [Image] Last update February 19, 2002 at 04:00 UTC. [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, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update February 2, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update February 2, 2002)] [Historical solar and geomagnetic data charts 1954-2001 (last update January 12, 2002)] Recent development The geomagnetic field was quiet to active on February 18. Solar wind speed ranged between 337 and 391 km/sec. Solar flare activity was moderate. Solar flux was 192.8, the planetary A index was 9 (3-hour K indices: 1222 1334, Boulder K indices: 1222 2334). Region 9824 was quiet and stable. Region 9825 decayed further with a significant reduction in area of the leading penumbra, the region appears to be losing all its trailing spots. Region 9830 developed further and has several magnetic delta structures, one in the main penumbra and others in spot sections north and northeast of the leading penumbra. The flare potential has increased and further M class flares are likely. There is a possibility for a major flare as well. New region 9832 just northeast of region 9830 was finally numbered by SEC/NOAA, the region is decaying and could soon become spotless. Flares and CMEs A total of 1 C and 1 M class events were recorded on February 18. Spotless region 9829 produced a C5.9/1F flare at 07:57. Region 9830 was the source of a long duration M1.0 event peaking at 21:15 UTC. With LASCO images from the hours after this event not yet available it is difficult to tell if there was any significant CME associated with the LDE. The background x-ray flux is at the class B7 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on February 19-21. 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 Location region numbered no. at Area Classification Comment sunspots midnight 9822 2002.02.08 N17W70 plage 9824 2002.02.09 1 N23W48 0110 HAX beta-gamma area too high, the 9825 2002.02.09 10 N14W51 0230 FAO penumbral coverage is just slightly more than region 9824 9826 2002.02.10 S22W67 plage 9828 2002.02.11 S15W44 plage 9829 2002.02.14 S05E23 plage 9830 2002.02.14 43 S18E20 0480 FKI beta-gamma-delta 9831 2002.02.16 S11W65 plage 9832 2002.02.18 9 S13E25 0020 BXO Total number of sunspots: 63 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.04 184.2 125.5 120.8 cycle 23 sunspot max. 2000.07 202.3 170.1 119.8 2000.12 173.6 104.4 112.0 (-0.7) 2001.01 166.6 95.6 108.7 (-3.3) 2001.02 146.6 80.6 104.1 (-4.6) 2001.03 177.7 113.5 104.8 (+0.7) 2001.04 177.7 107.7 107.6 (+2.8) 2001.05 147.1 96.6 108.7 (+1.1) 2001.06 173.0 134.0 109.8 (+1.1) 2001.07 131.3 82.2 111.7 (+1.9) 2001.08 162.9 106.8 (113.5 predicted, +1.8) 2001.09 233.2 150.7 (113.3 predicted, -0.2) 2001.10 207.6 125.6 (111.0 predicted, -2.3) 2001.11 210.6 106.5 (109.6 predicted, -1.4) 2001.12 235.1 131.8 (106.2 predicted, -3.4) 2002.01 226.6 113.9 (102.6 predicted, -3.6) 2002.02 209.1 (1) 130.1 (2) (101.2 predicted, -1.4) 1) Running average based on the daily 20:00 UT solar flux value at 2800 MHz. 2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official international sunspot number 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]