Solar Terrestrial Activity Report [Image] Last update March 13, 2000 at 04:50 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 minor storm on March 12. Solar wind speed ranged between 336 and 468 km/sec. A disturbance started after 07h UTC and was essentially over by 15h UTC. The source of the geomagnetic disturbance is not clear. Solar flare activity was moderate. Solar flux was 203.2, the planetary A index was 19 (3-hour K indices: 3354 4323, Boulder K indices: 3343 3413). Region 8898 was mostly unchanged and could produce further C flares or a minor M flare before rotating over the west limb on March 15. Region 8900 rotated out of view at the southeast limb. Regions 8901 and 8902 were quiet and stable, as was region 8903. Region 8904 developed slowly. Further C flares are likely and there is a possibility of a minor M flare. Region 8906 developed slowly and has a fairly good chance of producing a major flare. Region 8907 decayed and could become spotless today. Region 8908 decayed slowly and was quiet. Region 8909 was quiet and stable. New region 8910 rotated into view at the northeast limb. This region could produce C and minor M flares. Flares and CMEs 13 C flares and 1 M flare were recorded on March 12. Region 8904 produced a C2.3 flare at 03:05, a C4.7 at 04:31 and a C3.5 flare at 17:25 UTC. Region 8898 was the source of a C1.4 flare at 11:31 and a C6.4/1F flare at 18:51 UTC. Region 8906 was again the most active region and generated a C2.5 flare at 06:16, a C5.8 flare at 09:09, a C2.4 flare at 12:22, a C3.9 flare at 23:08 and finally an impulsive M3.6/1B flare at 23:38 UTC. The latter flare did not appear to be accompanied by a significant CME. 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 13-15. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 8898 20000302 11 S13W59 0310 EAO 8899 20000303 S13W87 plage 8900 20000304 S17W87 plage 8901 20000305 4 S12W22 0010 CSO 8902 20000306 1 S17W03 0010 HRX 8903 20000307 8 S12W46 0040 CAO 8904 20000308 12 N23W59 0170 EAO 8905 20000308 S06W31 plage 8906 20000308 41 S15E18 0850 FKC beta-gamma-delta 8907 20000308 1 S17W35 0010 AXX 8908 20000309 4 S20E33 0020 CSO 8909 20000311 2 S29E64 0040 HSX 8910 20000312 4 N11E68 0140 CAI beta-delta Total number of sunspots: 88 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 2000.03 212.1 (1) 75.3 (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]