Solar Terrestrial Activity Report [Image] Last update March 8, 2000 at 05:40 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update 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 unsettled to active on March 7. Solar wind speed ranged between 412 and 500 km/sec. A minor disturbance was in progress all day. Solar flare activity was moderate. Solar flux was 221.8, the planetary A index was 16 (3-hour K indices: 3344 3333, Boulder K indices: 3343 3333). Region 8889 was quiet and stable and will rotate over the west limb today. Region 8891 developed slowly and produced a few C flares. An M class flare is possible as this region rotates over the west limb. Region 8896 decayed into spotless plage. Region 8897 rotated off the visible disk. Region 8898 was mostly unchanged and quiet. The region has minor M class flare potential. Region 8899 was quiet and stable. Region 8900 did not change significantly and has minor M class flaring potential. Region 8901 was quiet and stable, as was region 8902. New region 8903 emerged in the southeast quadrant. A very active region at the southeast limb began rotating into view during the latter half of the day. Several spots are already visible and the region is likely to produce further M flares, perhaps even a major proton flare. Flares and CMEs 16 C flares and 2 M flares were recorded on March 7. Region 8891 produced a C6.3 flare at 14:30, a C8.7 flare at 22:02 and a C8.6 flare at 22:32 UTC. Almost all other flares had their origin in the region at the southeast limb. An M1.2/1F flare was observed at 16:07 UTC and was accompanied by a CME off the southeast limb. An M1.0 flare was recorded at 19:50 UTC, it was an impulsive event. An impulsive M1.4 flare occurred at 02:00 UTC on March 8, the likely source was the new region (8904) at the southeast limb. March 5: A filament eruption was observed over the central meridian near the solar equator starting at 07:48 UTC in LASCO-EIT. It is not clear whether there was a CME associated with this event, if there was it would likely impact Earth on March 8. March 4: A filament eruption started at 16:24 in LASCO EIT images to the southeast of regions 8899 and 8900. There is a small chance the associated CME could be geoeffective, any impact would most likely occur on March 8. The background x-ray flux is at the class C1 level. Coronal holes No obvious coronal holes are approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to active on March 8. There is a fairly small chance a minor CME could impact Earth today. 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 8889 20000224 2 N19W82 0010 BXO 8891 20000225 14 S17W67 0680 FKO 8892 20000226 N06W64 plage 8896 20000229 N20W30 plage 8897 20000301 1 S37W95 0000 AXX 8898 20000302 18 S13E07 0470 EKO 8899 20000303 7 S11W20 0040 DAO 8900 20000304 21 S16W26 0330 EAI beta-gamma 8901 20000305 8 S15E41 0020 BXO 8902 20000306 1 S17E60 0050 HSX 8903 20000307 2 S12E23 0030 DAO Total number of sunspots: 74 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 2000.03 216.4 (1) 41.9 (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]