Solar Terrestrial Activity Report [Image] Last update February 28, 2000 at 03:45 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] Recent development The geomagnetic field was quiet to unsettled on February 27. Solar wind speed ranged between 560 and 651 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 227.3, the planetary A index was 10 (3-hour K indices: 3123 2332, Boulder K indices: 3222 2322). Region 8879 was mostly unchanged and could produce C flares and possibly a minor M flare. Region 8881 was mostly quiet and stable. Region 8882 developed slowly and could produce a major flare. Region 8883 decayed slowly and was quiet. Regions 8886 and 8887 developed slowly and were quiet. Region 8888 was quiet and stable. Region 8889 decayed slowly and simplified, the region could produce a minor M flare. Region 8891 developed further and probably has the largest flare potential of the regions on the disk. An isolated X class flare is possible. Region 8892 was quiet and stable, as was region 8893. Flares and CMEs 5 C flares were recorded on February 27. Region 8879 produced a C3.3 flare at 12:20 UTC. Region 8882 was the source of a C4.0 flare at 06:12, a C2,5 flare at 15:50, a C1.4 flare at 16:26 and a C2.1 flare at 23:07 UTC. The background x-ray flux is at the class B9 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 28-29. 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 no. Location at region numbered sunspots midnight Area Classification Comment 8879 20000217 9 N23W52 0270 CSO 8881 20000221 8 N19W31 0050 DSO 8882 20000221 26 S16W05 0800 EKC 8883 20000222 7 N12W08 0080 CSO 8886 20000223 8 S14W24 0030 CSO 8887 20000224 5 S11E06 0010 BXO 8888 20000224 3 N36E18 0030 CAO 8889 20000224 5 N21E33 0350 EAO 8890 20000224 S11E25 plage 8891 20000225 15 S16E48 0870 EKI 8892 20000226 2 N06E53 0020 HSX 8893 20000226 3 S20W39 0000 BXO Total number of sunspots: 91 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.01 140.6 62.4 82.6 (+4.8) 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 (97.4 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 2000.02 170.7 (1) 147.8 (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]