Solar Terrestrial Activity Report [Image] Last update October 13, 2000 at 01:55 UTC. (Next major update will be posted just after noon on October 15 as I will be attending a DXLC board meeting this weekend.) [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 12. Solar wind speed ranged between 324 and 478 km/sec. A solar wind shock was observed at ACE at 21:46 UTC with solar wind speed increasing abruptly from 320 to 450 km/sec. The interplanetary magnetic field soon swung strongly to very strongly southwards and the geomagnetic field is at major storm levels early on October 13. Solar flare activity was moderate. Solar flux was 162.7, the planetary A index was 8 (3-hour K indices: 3122 2323, Boulder K indices: 3222 1213). Region 9181 decayed slowly and was quiet, the region could become spotless today. Region 9182 was mostly unchanged and may be capable of producing another M class flare before rotating over the west limb late on October 14. Region 9188 was quiet and stable, as was region 9189. Region 9190 developed slowly and could produce C flares. Region 9191 was quiet and stable and could become spotless today. Regions 9192 and 9193 developed slowly and were quiet. New region 9194 rotated into view at the southeast limb. New region 9195 emerged near the northwest limb and will rotate off the visible disk on October 14. New region 9196 emerged near the southwest limb. New region 9197 rotated partly into view at the northeast limb. Flares and CMEs A total of 2 C and 1 M class events were recorded on October 12. Region 9182 produced a C1.1/1F flare at 11:40 and an M1.5 long duration event peaking at 20:49 UTC. A fairly small CME was observed off the northwest limb following this event. The background x-ray flux is at the class C1 level. Coronal holes A coronal hole in the southern hemisphere will rotate into a geoeffective position on October 13-14. Forecast The geomagnetic field is expected to be unsettled to severe storm on October 13 and quiet to active on October 14. Quiet to unsettled is likely on October 15-16. A coronal stream will likely arrive late on October 16 and will last until October 18, unsettled to minor storm can be expected during this interval, perhaps with an isolated major storm interval. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor to useless. 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 9181 20001002 1 S27W60 0010 HSX 9182 20001002 12 N06W66 0310 DAI beta-gamma 9184 20001003 S14W54 plage 9187 20001008 N21W61 plage 9188 20001008 5 S10W22 0020 DSO 9189 20001008 4 N13E06 0020 DSO 9190 20001008 12 S18E20 0080 DAO 9191 20001010 1 N18E42 0010 AXX 9192 20001011 9 S13W12 0050 DAO 9193 20001011 9 N08W18 0030 DAO 9194 20001012 3 S13E60 0050 DSO 9195 20001012 3 N14W70 0030 DSO 9196 20001012 4 S31W54 0040 DSO 9197 20001012 4 N26E70 0020 CSO Total number of sunspots: 67 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 2000.10 167.6 (1) 57.1 (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]