Solar Terrestrial Activity Report [Image] Last update October 7, 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 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 unsettled on October 6. Solar wind speed ranged between 383 and 514 km/sec. Solar flare activity was low. Solar flux was 158.1, the planetary A index was 6 (3-hour K indices: 2112 2322, Boulder K indices: 2111 1011). Region 9172 was quiet and rotated off the visible disk. Region 9173 decayed slowly and was quiet, the region will rotate over the west limb today. Region 9176 decayed and was quiet. Region 9178 decayed slowly and was quiet. Region 9181 was quiet and stable, C class flares are possible. Region 9182 was quiet and stable. Region 9184 decayed into spotless plage. Region 9186 developed slowly and was mostly quiet. Flares and CMEs Only 1 C class event was recorded on October 6. It was an optically uncorrelated C2.4 flare at 10:11 UTC. The background x-ray flux is at the class B5 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 unsettled on October 7-8. A coronal stream could cause unsettled to active intervals on October 9-10. 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 no. Location at region numbered sunspots midnight Area Classification Comment 9172 20000924 1 N15W87 0050 HAX 9173 20000924 7 S11W80 0150 EAO 9175 20000926 N22W59 plage 9176 20000927 5 S10W53 0130 CSO 9178 20000928 11 S22W43 0150 CAO 9179 20000930 N36W68 plage 9180 20001001 S32W89 plage 9181 20001002 14 S28E16 0070 DAO 9182 20001002 13 N00E25 0140 ESO 9183 20001003 S32W69 plage 9184 20001003 S14E24 plage 9185 20001004 S18W62 plage 9186 20001004 6 N12W68 0130 DAO Total number of sunspots: 57 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 2000.10 185.4 (1) 33.2 (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]