Solar Terrestrial Activity Report [Image] Last update October 18, 2000 at 01:30 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 17. Solar wind speed ranged between 438 and 565 km/sec, generally decreasing all day. Solar flare activity was low. Solar flux was 154.1, the planetary A index was 9 (3-hour K indices: 3313 2232, Boulder K indices: 3213 3222). Region 9190 decayed slowly and was quiet. Region 9192 was quiet and stable. Region 9193 was mostly quiet and stable. Both region 9192 and 9193 will be rotating out of view at the west limb today. Region 9194 developed slowly and remained quiet, C class flares are possible. Region 9198 developed slowly and was quiet. Region 9199 was quiet and stable. Region 9200 could produce further C class flares. New region 9201 rotated into view at the northeast limb. Flares and CMEs A total of 3 C class events were recorded on October 17. Region 9193 produced a long duration C3.0 event peaking at 02:04 UTC. Region 9200 generated a C2.2 flare at 17:59 UTC. A long duration C4.2 event peaked at 22:06 UTC. The background x-ray flux is at the class B6 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on October 18-20. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to 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 9188 20001008 S07W87 plage 9189 20001008 N14W58 plage 9190 20001008 3 S14W48 0050 HAX 9191 20001010 N18W23 plage 9192 20001011 1 S11W78 0000 AXX 9193 20001011 5 N05W86 0110 DAO 9194 20001012 19 S11W04 0080 DAO 9197 20001012 N25E03 plage 9198 20001014 9 S31E26 0100 DAO 9199 20001015 1 N12E41 0020 HSX 9200 20001016 7 S18E46 0100 DSO 9201 20001017 5 N16E69 0080 CSO Total number of sunspots: 50 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 2000.10 165.2 (1) 78.5 (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]