Solar Terrestrial Activity Report [Image] Last update February 27, 2000 at 04:40 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 active on February 26. Solar wind speed ranged between 589 and 727 km/sec under the influence of a high speed coronal stream. Solar flare activity was moderate. Solar flux was 214.8, the planetary A index was 12 (3-hour K indices: 3243 2333, Boulder K indices: 2333 2323). 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, the region now has a magnetic delta configuration. Region 8883 decayed slowly and was quiet. Region 8885 decayed into spotless plage. Regions 8886 and 8887 were quiet and stable. Region 8888 seems to be decaying and was quiet. Region 8889 is a complex region capable of producing a major flare. Region 8890 decayed into spotless plage. Region 8891 rotated fully into view revealing a very large penumbra with several umbra inside. The region has major flare potential, even X class flares are possible. New region 8892 rotated into view at the northeast limb at a low latitude. New region 8893 emerged in the southwest quadrant. Flares and CMEs 3 C flares and 1 M class event were recorded on February 26. Region 8889 produced a C2.6 at 06:24 UTC. Region 8891 was the source of a C4.4 flare at 22:24 UTC. A prominence erupted at the northeast limb near the end of the day and generated an M1.0 long duration event. A large coronal mass ejection was observed over the north pole and the northeast limb. The background x-ray flux is at the class C1 level. Coronal holes A large trans equatorial coronal hole was in a geoeffective position on February 21-25. Forecast The geomagnetic field is expected to be quiet to unsettled on February 27-28 with a chance of isolated active intervals. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor to 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 Location region numbered no. at Area Classification Comment sunspots midnight 8876 S11W82 plage 8879 20000217 7 N22W39 0250 DSO 8881 20000221 10 N19W17 0040 DAO 8882 20000221 22 S16E07 0650 EKI beta-gamma-delta 8883 20000222 14 N13E07 0090 DSO 8885 20000223 N11W83 plage 8886 20000223 2 S14W09 0000 BXO 8887 20000224 2 S11E19 0020 HSX 8888 20000224 2 N36E30 0030 CSO 8889 20000224 7 N21E45 0370 FSO 8890 20000224 S11E38 plage 8891 20000225 15 S14E60 0720 EKC 8892 20000226 1 N05E64 0040 HSX 8893 20000226 1 S20W26 0000 AXX Total number of sunspots: 83 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 2000.02 168.6 (1) 140.8 (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]