Solar Terrestrial Activity Report [Image] Last update October 23, 2000 at 04:50 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 October 20, 2000)] Recent development The geomagnetic field was quiet to active on October 22. Solar wind speed ranged between 355 and 608 km/sec. A coronal stream based disturbance arrived at ACE at approximately 08h UTC. Solar flare activity was low. Solar flux was 160.2, the planetary A index was 13 (3-hour K indices: 1113 4443, Boulder K indices: 0013 3432). Region 9198 was quiet and stable, occasional C class flaring is possible. Region 9199 decayed further but could still produce occasional C class flares. Region 9200 decayed and was quiet. Region 9201 was mostly unchanged and could produce C flares and occasional minor M class flares. Region 9202 was quiet and stable, as was region 9203. Regions 9204 and 9205 decayed into spotless plage. A small spotted region has rotated into view at the northeast limb. Fairly intense emissions are being observed over the southeast limb and an interesting region could rotate into view over the next 2-3 days. Flares and CMEs A total of 4 C class events were recorded on October 22. Region 9203 was the source of a long duration C3.6 event which peaked at 02:31 UTC. A CME may have produced as well., however, LASCO images have been unavailable since late on Saturday. Region 9199 produced a C1.8 flare at 04:48 UTC. Region 9201 generated a C1.8 flare at 21:09 UTC. A filament eruption occurred in the northeast quadrant early on October 23, approximately a day's rotation away from the central meridian. Again we will have to wait for LASCO image availability to determine if there was any potentially geoeffective CME. 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 active on October 23. 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 9191 20001010 N18W88 plage 9194 20001012 S11W67 plage 9197 20001012 N25W62 plage 9198 20001014 11 S29W37 0160 DSI 9199 20001015 9 N09W31 0040 DAO 9200 20001016 3 S15W20 0010 HSX 9201 20001017 31 N17E06 0250 EAI 9202 20001018 2 N10W24 0010 AXX 9203 20001020 1 N13W43 0010 HSX 9204 20001020 N10W12 plage 9205 20001021 N36W33 plage 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 (121.0 predicted, +1.2) 2000.05 184.9 120.8 (121.3 predicted, +0.3) 2000.06 179.8 124.9 (122.8 predicted, +1.5) 2000.07 202.3 169.1 (124.9 predicted, +2.1) 2000.08 163.0 130.5 (125.0 predicted, +0.1) 2000.09 182.1 109.9 2000.10 163.5 (1) 100.5 (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]