Solar Terrestrial Activity Report [Image] Last update February 29, 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] Recent development The geomagnetic field was quiet to slightly active on February 28. Solar wind speed ranged between 563 and 726 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 218.8, the planetary A index was 12 (3-hour K indices: 3332 4322, Boulder K indices: 2432 3432). Region 8879 decayed slowly and was quiet. Region 8881 was mostly quiet and stable. Region 8882 increased its areal coverage slowly and is still capable of producing a major flare. Region 8883 decayed slowly and was quiet. Region 8886 was quiet and stable. Region 8887 decayed into spotless plage. Region 8888 was quiet and stable. Region 8889 did not change significantly and was quiet, the region could produce a minor M flare. Region 8891 developed further and has major flare potential. Region 8892 was quiet and stable, as was region 8893. New region 8894 emerged in the southwest quadrant. An active region is rotating into view at the northeast limb. Flares and CMEs 3 C flares were recorded on February 28, none of them were significant or could be optically assigned to any of the visible regions. A fast coronal mass ejection from behind the west limb may have been associated with a type II sweep just before noon. The background x-ray flux is at the class B8 level. Coronal holes A small coronal hole in the northern hemisphere may have been in a geoeffective position on February 28. Forecast The geomagnetic field is expected to be quiet to unsettled on February 29 and mostly quiet on March 1. 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 3 N23W65 0200 CSO 8881 20000221 6 N19W44 0050 DSO 8882 20000221 21 S16W18 0950 DKI beta-gamma 8883 20000222 4 N12W22 0060 DSO 8886 20000223 8 S13W37 0040 CSO 8887 20000224 S11W04 plage 8888 20000224 2 N36E06 0030 CSO 8889 20000224 6 N21E19 0370 FSO 8890 20000224 S11E12 plage 8891 20000225 19 S15E35 0990 EKI beta-gamma 8892 20000226 4 N06E39 0000 CSO 8893 20000226 1 S19W54 0000 AXX 8894 20000228 2 S33W66 0000 AXX Total number of sunspots: 76 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 2000.02 172.4 (1) 154.2 (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]