Solar Terrestrial Activity Report [Image] Last update March 25, 2002 at 05:15 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update March 4, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update March 4, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update March 4, 2002)] [Historical solar and geomagnetic data charts 1954-2001 (last update January 12, 2002)] Recent development The geomagnetic field was unsettled to major storm on March 24. Solar wind speed ranged between 368 and 483 km/sec. A moderate to strong geomagnetic disturbance was in progress most of the day with decreasing activity observed during the last quarter of the day. A possible solar wind shock was observed at ACE at 00:58 UTC on March 25. This did not record as a solar wind shock at SOHO. Solar wind speed did increase suddenly but there was no change in the very low solar wind density. The source of the shock is likely a full halo CME observed after a an event near the southwest limb on March 22. Solar flare activity was low. Solar flux was 175.3, the planetary A index was 47 (3-hour K indices: 5566 4533, Boulder K indices: 4565 4433). Region 9871 decayed slowly and quietly. Region 9875 decayed slowly and quietly. Region 9876 developed slowly and could produce minor M class flares. Region 9878 was mostly unchanged and quiet. The region could produce minor M class flares. Region 9879 rotated quietly over the northwest limb. Region 9880 developed at a moderate pace and was quiet. Region 9881 developed quickly and could soon become capable of producing minor M class flares. A magnetic delta structure appears to be forming. Region 9882 did not change significantly and was quiet. Region 9883 was quiet and stable. Flares and CMEs A total of 5 C class events were recorded on March 24. Region 9876 produced a C5.1 flare at 00:38 UTC. Region 9881 generated a C4.5 flare at 20:36 UTC. The background x-ray flux is at the class B8 level. Coronal holes A small coronal hole in the northern hemisphere was in a geoeffective position on March 24. A recurrent trans equatorial coronal hole will rotate into a geoeffective position on March 29-31. Forecast The geomagnetic field is expected to be quiet to active on March 25 with a possibility of minor storm intervals and quiet to unsettled on March 26. A weak coronal stream related disturbance could start on March 27. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very 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 9871 2002.03.13 6 S18W72 0100 DAO 9874 2002.03.19 N18W43 plage 9875 2002.03.19 5 S20W06 0090 DAO 9876 2002.03.20 23 S15E18 0140 EAI 9877 2002.03.20 N15W83 plage 9878 2002.03.20 16 N09E28 0100 ESI beta-gamma 9879 2002.03.21 5 N14W88 0060 DAO 9880 2002.03.21 10 N07W08 0020 CSO area much too small! classification wrong 9881 2002.03.22 7 S03W34 0020 CSO area much too small! classification wrong 9882 2002.03.22 6 N16E41 0090 DAO 9883 2002.03.23 1 N06E58 0050 HSX Total number of sunspots: 79 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 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) 2001.08 162.9 106.8 113.6 (+1.8) 2001.09 233.2 150.7 (113.7 predicted, +0.1) 2001.10 207.6 125.6 (111.7 predicted, -2.0) 2001.11 210.6 106.5 (110.2 predicted, -1.5) 2001.12 235.1 131.8 (106.9 predicted, -3.3) 2002.01 226.6 113.9 (103.3 predicted, -3.6) 2002.02 205.0 108.0 (101.9 predicted, -1.4) 2002.03 179.5 (1) 116.5 (2) (97.6 predicted, -4.3) 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 25-45% 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]