Solar Terrestrial Activity Report [Image] Last update March 23, 2000 at 04:55 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 2, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update March 2, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update March 2, 2000)] [Historical solar and geomagnetic data charts 1954-1999] Recent development The geomagnetic field was quiet to unsettled on March 22. Solar wind speed ranged between 354 and 644 km/sec under the influence of a high speed coronal stream. Solar flare activity was high. Solar flux was 233.8, the planetary A index was 11 (3-hour K indices: 2223 3333, Boulder K indices: 1322 2422). Region 8910 was mostly unchanged and may be capable of producing another major flare before rotating off the visible disk on March 25. Region 8913 decayed slowly and could still produce a minor M class flare. Region 8915 was quiet and stable. Region 8916 appears to be slowly decaying but still has a chance of producing a minor M flare. Region 8917 developed slowly and is capable of producing a minor M flare. Region 8918 developed quickly early in the day and could generate an M class flare over the next couple of days. Region 8919 once again decayed into spotless plage. Region 8920 was quiet and stable. Region 8921 developed quickly and could be capable of producing a major flare. Region 8922 was quiet and stable. New region 8923 emerged in the southeast quadrant near region 8921. An active region is rotating into view at the northeast limb. Several other regions are likely to rotate into view over the next 2-3 days. Flares and CMEs A total of 6 C flares, 1 M flare and 1 X flare were recorded on March 22. Region 8910 produced an M1.9 flare at 01:18, a C5.1 flare at 13:11 and an X1.1/2N impulsive flare at 18:48 UTC. The latter flare was accompanied by strong type II and IV sweeps and a coronal mass ejection off the west limb. Region 8917 was the source of a C5.5 flare at 07:21, a C7.7 flare at 17:44 and a C3.5 flare at 18:20 UTC. Region 8913 generated a C9.3 flare at 11:07 UTC. An impulsive M1.3 flare was observed at 00:30 UTC on March 23. The background x-ray flux is at the class C2 level. Coronal holes The large coronal hole that has been around for several months has split into three smaller coronal holes. One is in the northern hemisphere and was in a geoeffective position on March 19, another (fairly small and closing because of development in region 8913) is in the southern hemisphere and was in a geoeffective position on March 20. The third, and largest remaining part, is trans equatorial and was in a geoeffective position on March 21-22. Forecast The geomagnetic field is expected to be quiet to active on March 23-25 due to coronal streams. 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 8909 20000311 S28W67 plage 8910 20000312 25 N13W61 0810 EKC beta-gamma-delta 8913 20000314 17 S16W38 0190 EAI 8914 20000316 N16W73 plage 8915 20000316 2 N23W01 0210 HAX 8916 20000317 13 N12E14 0240 EAO 8917 20000318 17 N20W35 0250 DAI 8918 20000319 13 N32W53 0460 EHO 8919 20000319 S21E17 plage 8920 20000320 5 N24E30 0020 BXO 8921 20000320 14 S17E48 0370 DAO 8922 20000321 3 N13E44 0030 CRO 8923 20000322 3 S27E43 0010 BXO Total number of sunspots: 112 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.02 141.9 66.1 84.6 (+2.0) 1999.03 126.3 69.1 83.8 (-0.8) 1999.04 117.2 63.9 85.4 (+1.6) 1999.05 148.4 106.3 90.4 (+5.0) 1999.06 169.8 137.7 93.0 (+2.6) 1999.07 165.6 113.5 94.4 (+1.4) 1999.08 170.7 93.7 97.5 (+3.1) 1999.09 135.7 71.5 (102.6 predicted, +5.1) 1999.10 164.8 116.4 (107.7 predicted, +5.1) 1999.11 191.5 132.7 (110.2 predicted, +2.5) 1999.12 169.8 86.4 2000.01 158.1 90.2 2000.02 174.1 112.3 2000.03 206.7 (1) 133.8 (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 in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]