Solar Terrestrial Activity Report [Image] Last update March 12, 2000 at 04:25 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 active on March 11. Solar wind speed ranged between 335 and 408 km/sec. Solar flare activity was moderate. Solar flux was 203.2, the planetary A index was 12 (3-hour K indices: 3342 4222, Boulder K indices: 3332 3322). Region 8898 was mostly unchanged and quiet. The region has minor M class flare potential. Region 8899 decayed into spotless plage. Region 8900 decayed further and was mostly quiet, the region will rotate off the visible disk on March 13. Regions 8901 and 8902 were quiet and stable. Region 8903 decayed slowly and was quiet. Region 8904 developed slowly and could produce further C flares and has minor M flare potential. Region 8905 decayed into spotless plage. Region 8906 did not change significantly and remains capable of generating a major flare. Region 8907 was quiet and stable, as was region 8908. New region 8909 rotated into view at the southeast limb. A fairly active region near the solar equator is rotating into view at the east limb. Flares and CMEs 10 C flares and 1 M flare were recorded on March 11. Region 8904 produced a C4.5 flare at 14:42 and a C6.9 flare at 21:34 UTC. Region 8900 generated a long duration C5.9 event peaking at 15:42 UTC. Region 8906 was the source of an M1.3/1N flare at 09:27 UTC, a C5.7 flare at 11:14, a C3.4 flare at 00:19 and a long duration C2.6 event peaking at 17:18 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 with occasional active intervals on March 12-14. 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 N20W82 plage 8898 20000302 17 S13W45 0370 EAI 8899 20000303 S13W74 plage 8900 20000304 4 S17W74 0060 CSO 8901 20000305 1 S12W13 0010 HSX 8902 20000306 1 S17E10 0020 HSX 8903 20000307 6 S12W31 0040 DSO 8904 20000308 18 N24W45 0130 ESO 8905 20000308 S06W18 plage 8906 20000308 22 S16E31 0800 DKC beta-delta 8907 20000308 5 S18W20 0020 CSO 8908 20000309 3 S19E45 0040 CSO 8909 20000311 1 S29E76 0030 HRX Total number of sunspots: 78 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 2000.03 212.9 (1) 69.2 (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]