Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update February 5, 2000 at 04:10 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 on February 4. Solar wind speed ranged between 379 and 432 km/sec. Solar flare activity was moderate. Solar flux was 167.4, the planetary A index was 4 (3-hour Kp indices: 2020 2121, Boulder K indices: 2120 2212). Region 8848 decayed and was quiet. Region 8851 developed slowly and will likely continue to produce occasional C flares, a minor M flare is possible as well. Region 8853 decayed and was quiet. Region 8854 did not change significantly and could produce C flares. Region 8855 decayed into spotless plage. Region 8856 was quiet and stable. Region 8857 developed slowly and was quiet. Region 8858 developed slowly and will likely continue to produce C flares and occasional M flares. Region 8859 developed further and could produce C flares before rotating over the west limb on February 6. New region 8860 emerged in the northeast quadrant near the central meridian. Flares and CMEs 17 C flares and 1 M flare were recorded on February 4. Region 8858 produced most of the flares. The most significant ones were an M3.0 impulsive flare at 09:19 UTC, a C4.9 flare at 18:02 UTC and a long duration C7.0/1F event peaking at 19:50 UTC. The background x-ray flux is at the class B7 level. Coronal holes A trans equatorial coronal hole was in a geoeffective position on February 2-4. Forecast The geomagnetic field is expected to be quiet to unsettled on February 5. Unsettled to active is likely on February 6-7 due to a coronal stream. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally fair. 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 8846 20000126 N37W66 plage 8848 20000126 1 S08W43 0050 HSX 8849 20000128 S17W71 plage 8850 20000130 S17W41 plage 8851 20000130 19 N25W22 0150 DSO 8852 20000131 N10W38 plage 8853 20000201 3 S12E29 0010 AXX 8854 20000201 3 S35E46 0100 DAO 8855 20000202 N17E28 plage 8856 20000202 3 S13E59 0120 ESO 8857 20000203 5 S19W10 0040 DAO 8858 20000203 5 N26E64 0090 DSO 8859 20000203 2 N22W66 0060 DAO 8860 20000204 5 N26E06 0010 BXO Total number of sunspots: 46 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 2000.02 151.0 (1) 17.9 (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]