Solar Terrestrial Activity Report [Image] Last update October 16, 2000 at 04:45 UTC. Minor update posted at 17:08 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 15. Solar wind speed ranged between 460 and 563 km/sec. Solar wind speed increased noticeably after 23h UTC, probably because of the arrival of a coronal stream. Solar flare activity was low. Solar flux was 161.1, the planetary A index was 8 (3-hour K indices: 2211 2333, Boulder K indices: 1211 3333). Region 9188 decayed into spotless plage. Region 9190 decayed slowly and was quiet. Region 9192 was quiet and stable. Region 9193 decayed slowly and was quiet. Region 9194 developed slowly and could produce C class flares. Region 9198 could produced further C class flares. New region 9199 rotated into view at the northeast limb. Comment added at 17:08 UTC on October 16: A very long duration M2.5 event peaked at 07:28 UTC, this was a minor proton producing event too with the above 10 MeV proton flux so far having peaked near 14 pfu. The source was likely in region 9182, just behind the west limb. A huge full halo coronal mass ejection was observed in LASCO images as well. Although it appears unlikely, there is a small possibility this CME could affect the geomagnetic field on October 19. The geomagnetic field has been quiet to active, the coronal stream related disturbance could intensify late today. Flares and CMEs A total of 7 C class events were recorded on October 15. Region 9198 produced C1.7 flares at 17:44 and 18:43 UTC. October 14: A full halo CME was observed starting at 06:51 UTC in LASCO C2 images. No corresponding activity was observed in LASCO EIT so this was probably a back side event. The background x-ray flux is at the class C1 level. Coronal holes A coronal hole in the southern hemisphere was in a geoeffective position on October 13-14. Forecast The geomagnetic field is expected to be unsettled to minor storm today and on October 17 due to a coronal stream. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 9188 20001008 S07W61 plage 9189 20001008 N14W32 plage 9190 20001008 8 S17W19 0070 CSO 9191 20001010 N18E03 plage 9192 20001011 6 S13W51 0020 BXO 9193 20001011 7 N05W61 0150 DSO 9194 20001012 13 S12E23 0120 DAI 9197 20001012 N25E29 plage 9198 20001014 4 S31E54 0080 CSO Old 9199 20001015 1 N12E68 0040 HSX region 9169 Total number of sunspots: 39 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 2000.10 166.2 (1) 70.8 (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]