Solar Terrestrial Activity Report [Image] Last update March 29, 2002 at 04:15 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 quiet to unsettled on March 28. Solar wind speed ranged between 335 and 394 km/sec. Solar flare activity was low. Solar flux was 176.2, the planetary A index was 6 (3-hour K indices: 1012 3331, Boulder K indices: 0001 3211). Region 9875 decayed and was spotless by late evening. Region 9876 decayed significantly and was quiet. Region 9878 decayed and lost more than half of its spots. The region simplified and is not likely to produce any significant flares. Region 9880 developed slowly and could generated M class flares. Region 9881 rotated off the visible disk and was quite active during the latter half of the day. Region 9883 was quiet and stable. Region 9884 developed slowly and quietly. Region 9885 developed slowly and could produce minor M class flares. SEC/NOAA failed to number a new region just east of region 9885 and a new region rotating into view at the southeast limb. Flares and CMEs A total of 9 C class events were recorded on March 28. Spotless region 9882 produced a C1.4 flare at 10:02 UTC. Region 9885 generated a C1.6 flare at 15:43 UTC. Region 9881 at the southwest limb was the source of a C7.6 flare at 18:00 UTC, the source of the flare was clearly evident in LASCO/EIT images. The background x-ray flux is at the class B7 level. Coronal holes A large recurrent trans equatorial coronal hole will be in a geoeffective position on March 28-30. Forecast The geomagnetic field is expected to be quiet to unsettled on March 29-30. A coronal stream will likely reach the Earth on March 31 and cause unsettled to active conditions, perhaps with a few isolated minor storm intervals. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair. 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 region numbered sunspots at Area Classification Comment midnight 9875 2002.03.19 1 S21W62 0010 HSX now spotless 9876 2002.03.20 26 S14W35 0130 EAI 9878 2002.03.20 9 N09W26 0080 EAO 9880 2002.03.21 13 N09W63 0210 DAO beta-gamma 9881 2002.03.22 1 S03W87 0060 HSX 9882 2002.03.22 N16W12 plage 9883 2002.03.23 1 N06E04 0020 HSX 9884 2002.03.27 7 S19E25 0040 CRO 9885 2002.03.27 6 N11E56 0190 DSO beta-gamma Total number of sunspots: 64 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) 2002.03 178.2 (1) 136.8 (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]