Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update February 7, 2000 at 03:30 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 unsettled to minor storm on February 6. Solar wind speed ranged between 492 and 693 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 177.7, the planetary A index was 24 (3-hour Kp indices: 4445 4434, Boulder K indices: 3434 3434). Region 8848 was quiet and stable, the region will rotate off the visible disk on February 8. Region 8851 decayed slowly but could still produce occasional C flares. Region 8853 was quiet and stable. Region 8854 decayed slowly and was quiet. Region 8856 was quiet and stable. Region 8857 was quiet and mostly stable. Region 8858 added some spots and retained its delta configuration. M flares are possible from this region, as is an additional X class flare. Region 8860 decayed and could become spotless today. Region 8861 developed slowly and could produce further C flares. New region 8862 rotated partly into view at a low latitude at the southeast limb. This region could be capable of M class flaring as the corona as quite hot above the region. Flares and CMEs 10 C flares were recorded on February 6. Region 8851 produced a C2.4 flare and a C1.6 flare at 16:48 and 18:53 UTC respectively. Region 8861 was the source of a C1.4 flare (at 21:07 UTC) and a C1.3 flare (at 22:03 UTC). Spotless region 8855 generated a C1.8 flare at 12:08 UTC while region 8858 managed a C2.2 flare at 02:26 UTC and a C1.7 flare at 07:18 UTC. 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 unsettled to minor storm on February 7 and quiet to unsettled February 8-9. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally very 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 8848 20000126 4 S08W70 0090 CSO 8850 20000130 S17W67 plage 8851 20000130 12 N24W48 0080 DSO 8852 20000131 N10W64 plage 8853 20000201 5 S13W01 0010 BXO 8854 20000201 6 S34E23 0040 CSO 8855 20000202 N17E02 plage 8856 20000202 4 S13E32 0120 EAO 8857 20000203 7 S17W36 0010 CRO 8858 20000203 21 N27E40 0120 EAO gamma-delta 8860 20000204 1 N30W20 0000 AXX 8861 20000205 12 N07W27 0020 DRO 8862 20000206 1 S04E75 0090 HSX Total number of sunspots: 73 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 2000.02 158.3 (1) 29.1 (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]