Solar Terrestrial Activity Report [Image] Last update February 24, 2002 at 05:50 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 on February 23. Solar wind speed ranged between 327 and 452 km/sec. Solar flare activity was low. Solar flux was 188.2, the planetary A index was 4 (3-hour K indices: 2110 1221, Boulder K indices: 2211 1212). Region 9830 did not change much and remains capable of producing M class flares. Region 9837 was mostly unchanged and quiet. Region 9839 developed slowly and quietly. Region 9840 was quiet and is slowly decaying, the region could soon become spotless. Region 9841 decayed slowly during the last half of the day. Region 9842 appears to be decaying and could soon become spotless. Region 9843 was quiet and is decaying, the region could soon become spotless. New region 9844 emerged at a moderate pace in the northeast quadrant. New region 9845 rotated into view at the northeast limb. Flares and CMEs A total of 9 C class events were recorded on February 23. Region 9839 produced a C2.2 flare at 04:43 UTC. Region 9841 generated a C4.9 flare at 06:30 UTC. Region 9830 was the source of a C2.6 flare at 08:12, a C2.1 flare at 11:58, a C4.3 flare at 14:00 and a C7.0 flare at 22:50 UTC. The background x-ray flux is at the class B8 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 24-26. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to good. 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 9829 2002.02.14 S06W40 plage 9830 2002.02.14 34 S19W49 0480 FAI beta-gamma-delta 9832 2002.02.18 S15W42 plage 9833 2002.02.19 N11W68 plage 9834 2002.02.19 N03E00 plage 9836 2002.02.20 S02W65 plage 9837 2002.02.20 8 N09E32 0080 DAO 9838 2002.02.21 5 N05W45 0030 CSO 9839 2002.02.21 6 S18W20 0030 CSO 9840 2002.02.21 2 S11E46 0040 CSO 9841 2002.02.22 9 S20W33 0070 DAO 9842 2002.02.22 2 S18W11 0010 HRX 9843 2002.02.22 4 S26E46 0050 CAO 9844 2002.02.23 4 N22E33 0040 CSO 9845 2002.02.23 2 N15E71 0080 HAX Total number of sunspots: 76 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) 2002.02 205.5 (1) 157.7 (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]