Solar Terrestrial Activity Report [Image] Last update October 9, 2000 at 03:50 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update October 2, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update October 2, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update October 2, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update August 10, 2000)] Recent development The geomagnetic field was quiet to slightly unsettled on October 8. Solar wind speed ranged between 325 and 368 km/sec. Solar flare activity was low. Solar flux was 148.9, the planetary A index was 5 (3-hour K indices: 1111 2223, Boulder K indices: 0000 0102). Region 9176 was quiet and stable, the region will rotate off the visible late today. Region 9178 was quiet and stable, the region will rotate over the west limb on October 10. Region 9181 was mostly unchanged and could generate occasional C class flares. Region 9182 was quiet and stable. Region 9186 was quiet and rotated off the visible disk. New region 9187 emerged in the northwest quadrant near the central meridian. New region 9188 emerged in the southeast quadrant, the region is spotless early on October 9. New region 9189 emerged in the northeast quadrant. New region 9190 rotated partly into view at the southeast limb. Flares and CMEs A total of 2 C class events were recorded on October 8, none of the flares were optically correlated. The background x-ray flux is at the class B4 level. Coronal holes A small coronal hole in the northern hemisphere was in a geoeffective position on October 6-7. Forecast The geomagnetic field is expected to be quiet to active on October 9-10 due to a coronal stream. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair. 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 9175 20000926 N22W85 plage 9176 20000927 6 S06W79 0220 DAO 9178 20000928 4 S18W73 0080 CSO 9181 20001002 7 S30W12 0100 DSO 9182 20001002 7 N02W02 0090 ESO 9184 20001003 S14W02 plage 9185 20001004 S18W88 plage 9186 20001004 2 N17W93 0090 DSO 9187 20001008 3 N21W07 0010 CSO 9188 20001008 2 S12E32 0010 CSO 9189 20001008 5 N19E54 0030 CSO 9190 20001008 2 S20E74 0060 DSO Total number of sunspots: 38 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.09 135.7 71.5 102.3 (+4.8) 1999.10 164.8 116.7 107.8 (+5.5) 1999.11 191.5 133.2 110.9 (+3.1) 1999.12 169.8 84.6 111.0 (+0.1) 2000.01 158.1 90.1 112.8 (+1.8) 2000.02 174.1 112.9 116.6 (+3.8) 2000.03 208.2 138.5 119.8 (+3.2) 2000.04 184.2 125.3 (121.7 predicted, +1.9) 2000.05 184.9 120.8 (122.5 predicted, +0.8) 2000.06 179.8 124.9 (124.1 predicted, +1.6) 2000.07 202.3 169.1 (126.2 predicted, +2.1) 2000.08 163.0 130.6 (124.8 predicted, -1.4) 2000.09 182.1 109.9 2000.10 177.1 (1) 40.4 (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]