Solar Terrestrial Activity Report [Image] Last update March 11, 2000 at 05:10 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 slightly active on March 10. Solar wind speed ranged between 356 and 412 km/sec. Solar flare activity was low (however, the number of C flares, 26, during the day was the highest of any day during cycle 23). Solar flux was 203.4 (the fifteenth consecutive day with solar flux above the 200 level), the planetary A index was 10 (3-hour K indices: 1013 3324, Boulder K indices: 1113 3323). Region 8898 decayed slowly and was quiet. The region has at minor M class flare potential. Region 8899 decayed and produced a couple of C flares, the region could become spotless today. Region 8900 decayed slowly and could produce further C flares and perhaps an isolated minor M flare. Regions 8901 and 8902 were quiet and stable. Region 8903 was quiet and stable. Region 8904 developed further and may be capable of minor M class flaring. Region 8905 was quiet and stable. Region 8906 developed fairly quickly and has major flare potential. Region 8907 was quiet and stable, as was region 8908. Flares and CMEs 26 C flares were recorded on March 10. Region 8899 produced a C2.0 flare at 09:12 and a C1.8 flare at 16:26 UTC. Region 8900 was the origin of a C3.6 flare at 05:44 and a C2.6 flare at 17:14 UTC. Region 8906 generated most of the remaining flares including a C7.7 flare at 17:58 UTC and a C7.4/1F flare at 21:08 UTC. The background x-ray flux is at the class C1 level. Coronal holes No obvious coronal holes are approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on March 11-13. 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 no. Location at region numbered sunspots midnight Area Classification Comment 8896 20000229 N20W69 plage 8898 20000302 21 S13W32 0420 EHI 8899 20000303 1 S13W61 0000 AXX 8900 20000304 17 S16W63 0210 FAI beta-gamma 8901 20000305 3 S12E01 0020 CRO 8902 20000306 3 S18E22 0010 AXX 8903 20000307 11 S12W17 0040 CRO 8904 20000308 24 N25W32 0100 CAO 8905 20000308 4 S06W05 0010 BXO 8906 20000308 29 S16E44 0730 DKC 8907 20000308 2 S16W06 0020 HRX 8908 20000309 6 S19E59 0070 CSO Total number of sunspots: 121 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 70.9 (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 2000.03 213.9 (1) 63.5 (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]