Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update February 8, 2000 at 04:45 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 7. Solar wind speed ranged between 590 and 711 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 181.9, the planetary A index was 25 (3-hour Kp indices: 4334 5443, Boulder K indices: 4344 4333). Region 8848 was quiet and stable, the region is rotating over the west limb. Region 8851 was mostly quiet and stable, occasional C flares are possible. Region 8853 was quiet and stable. Region 8854 decayed slowly and was quiet. Region 8855 reemerged with a couple of spots. Region 8856 was quiet and stable. Region 8857 developed slowly an could produce C flares. Region 8858 was mostly unchanged. Although the region is magnetically complex it was fairly quiet. M flares are possible, as is an additional X class flare. Region 8860 decayed into spotless plage. Region 8861 developed quickly and was quite active. Minor M class flaring is possible. Region 8862 rotated was quiet and stable. Another region at the southeast limb is about to rotate into view. Flares and CMEs 5 C flares were recorded on February 7. Region 8861 was the source of all optically correlated flares. The region produced a C4.4 flare at 16:54 UTC, a C1.2 flare at 18:18 UTC and a C4.3/1F flare at 23:28 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 quiet to unsettled on February 8-9 with the possibility of an isolated active interval early on Feb.8. 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 2 S10W83 0010 BXO 8850 20000130 S17W80 plage 8851 20000130 9 N23W61 0070 DSO 8852 20000131 N10W77 plage 8853 20000201 2 S15W15 0020 DSO 8854 20000201 3 S34E09 0020 CSO 8855 20000202 2 N18W13 0000 BXO 8856 20000202 6 S14E19 0110 ESO 8857 20000203 10 S18W48 0040 DRO 8858 20000203 19 N27E27 0110 DSO gamma-delta 8860 20000204 N30W33 plage 8861 20000205 15 N08W40 0220 DAO 8862 20000206 1 S05E61 0110 HAX Total number of sunspots: 69 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]