Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update February 9, 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 February 3, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update February 3, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update February 3, 2000)] [Historical solar and geomagnetic data charts 1954-1999] [Experimental solar data chart January 1998-September 1999] Recent development The geomagnetic field was quiet to unsettled on February 8. Solar wind speed ranged between 485 and 676 km/sec gradually decreasing most of the day. Solar flare activity was moderate. Solar flux was 173.6, the planetary A index was 12 (3-hour Kp indices: 3313 2333, Boulder K indices: 3313 2322). Region 8851 decayed slowly and was quiet, the region will rotate off the visible disk early on February 10. Region 8853 was quiet and stable, as were regions 8854 and 8855. Region 8853 is spotless early on Feb.9. Region 8856 could produce additional C class flares. Region 8857 was mostly unchanged and could generate occasional C flares. Region 8858 did not change significantly and remains capable of producing major flares. Region 8861 developed further and could be capable of minor M class flaring. Region 8862 was quiet and stable. New region 8863 rotated partly into view at the southeast limb. New region 8864 emerged in the northwest quadrant at a high latitude. New region 8865 emerged in the southeast quadrant. New region 8866 emerged near the northeast limb. Both regions 8864 and 8865 appear to be spotless early on Feb.9. Flares and CMEs 5 C flares and 1 M flare were recorded on February 8. Region 8861 produced a C1.1 flare at 00:49 UTC and a C1.4 flare at 02:06 UTC. Region 8856 generated a C1.6 flare at 05:26 UTC. Region 8858 was the source of a C3.3 flare at 12:38 UTC and an M1.3/1B long duration event peaking at 09:00 UTC. A strong type II sweep was associated with the latter event. LASCO C3 show a significant coronal mass ejection off the northeast limb and the north pole. Although the CME is probably not geoeffective, there is a minor chance it could be. In that case a grazing impact could occur on February 11 or 12. Region 8858 produced a long duration C6.6 event early on Feb.9 and may have been the source of a C5.3 flare as well. The background x-ray flux is at the class B7 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on February 9-10. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally 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 8851 20000130 5 N20W74 0020 BXO 8853 20000201 2 S13W27 0010 AXX 8854 20000201 4 S33W03 0010 CSO 8855 20000202 3 N17W26 0010 BXO 8856 20000202 8 S14E07 0110 EAO 8857 20000203 9 S18W59 0030 DRO 8858 20000203 17 N28E14 0100 CAO gamma-delta 8860 20000204 N30W46 plage 8861 20000205 13 N07W53 0290 DAO 8862 20000206 1 S05E48 0150 HAX 8863 20000208 3 S14E70 0040 CSO 8864 20000208 1 N44W16 0000 AXX 8865 20000208 1 S12E22 0000 AXX 8866 20000208 1 N18E64 0000 AXX Total number of sunspots: 68 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.01 140.6 62.0 82.6 (+4.7) 1999.02 141.9 66.3 84.6 (+2.0) 1999.03 126.3 68.8 83.8 (-0.8) 1999.04 117.2 63.7 85.4 (+1.6) 1999.05 148.4 106.4 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 (97.4 predicted, +3.0) 1999.09 135.7 70.9 (102.4 predicted, +5.0) 1999.10 164.8 116.4 (107.5 predicted, +5.1) 1999.11 191.5 132.7 1999.12 169.8 86.4 2000.01 158.1 90.2 2000.02 161.6 (1) 35.0 (2) 1) Running average based on the daily 20:00 UTC solar flux measurement at 2800 MHz by DRAO. 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]