Solar Terrestrial Activity Report [Image] Last update March 2, 2000 at 03:25 UTC. Last minor update posted at 13:54 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update March 2, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update March 2, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update March 2, 2000)] [Historical solar and geomagnetic data charts 1954-1999] Recent development The geomagnetic field was quiet to active on March 1. Solar wind speed ranged between 438 and 543 km/sec. A weak disturbance arrived shortly after 02h UTC. The interplanetary magnetic field strengthened and swung almost fully southwards. Solar flare activity was low. Solar flux was 232.8, the planetary A index was 19 (3-hour K indices: 2344 4433, Boulder K indices: 2434 4333). Region 8881 was quiet and stable. Region 8882 developed a magnetic delta configuration and could produce major flares over the next 3-4 days, the possibility of an X flare is increasing. Region 8883 was quiet and stable, as was region 8886. Region 8888 decayed and could become spotless within a day or two. Region 8889 did not change significantly and was mostly quiet, the region could produce a minor M flare. Region 8891 developed many new spots and a magnetic delta configuration. The flare potential is increasing and M or X flares over the next few days would not be surprising. Region 8892 was quiet and stable. Region 8893 decayed into spotless plage. Region 8894 rotated over the southwest limb (SEC/NOAA has, in their daily solar region summary, mistakenly moved this region to the position of region 8896 and awarded the region 19 spots. The daily sunspot number should be 218, not 247). Region 8895 was quiet and stable. Region 8896 developed slowly and was quiet. New region 8897 emerged in the southwest quadrant. A couple of active regions are at or are approaching the southeast limb. Comment added at 08:32 UTC on March 2: A major flare, an impulsive X1.1 event, peaked at 08:28 UTC. The source of the flare was region 8882. Further major flares are possible, both from region 8882 and 8891. Comment added at 09:22 UTC: Region 8886 has been developing quickly and produced an impulsive M1.0/1F flare at 08:43 UTC, this event may have been triggered by the X1.1/2B flare in region 8882 some minutes earlier. Comment added at 13:54 UTC: Region 8882 produced another major flare at 13:43 UTC, an impulsive M6.5 event. The X1.1 flare earlier today was accompanied by a very fast coronal mass ejection and a moderately strong type II sweep. Proton fluxes increased slightly above background values. Further major flares from region 8882 could start proton events at Earth. Flares and CMEs 8 C flares were recorded on March 1. Region 8882 produced the 2 optically assigned events of the day, a long duration C5.3 event peaking at 17:26 UTC and a C6.9 flare at 18:06 UTC. The background x-ray flux is at the class C1 level. Coronal holes A coronal hole in the northern hemisphere may be too far to the north to cause and geomagnetic disturbance when it rotates over the central meridian on March 6. Forecast The geomagnetic field is expected to be quiet to active on March 2 and quiet to unsettled on March 3-4. 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 Location region numbered no. at Area Classification Comment sunspots midnight 8881 20000221 3 N19W71 0060 CSO 8882 20000221 21 S15W45 0980 EKC beta-delta 8883 20000222 3 N12W48 0030 DSO 8886 20000223 9 S13W64 0050 BXO 8887 20000224 S11W30 plage 8888 20000224 2 N37W20 0000 AXX 8889 20000224 10 N20W07 0330 FAO 8890 20000224 S11W14 plage 8891 20000225 45 S16E08 0900 EKC beta-gamma-delta 8892 20000226 3 N06E14 0010 BXO 8893 20000226 S19W80 plage 8895 20000229 2 N14W62 0000 BXO 8896 20000229 8 N18E52 0080 DSO 8897 20000301 2 S35W12 0000 BXO Total number of sunspots: 108 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 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 97.5 (+3.1) 1999.09 135.7 70.9 (102.6 predicted, +5.1) 1999.10 164.8 116.4 (107.7 predicted, +5.1) 1999.11 191.5 132.7 (110.2 predicted, +2.5) 1999.12 169.8 86.4 2000.01 158.1 90.2 2000.02 174.1 112.3 2000.03 232.8 (1) 7.0 (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]