Solar Terrestrial Activity Report [Image] Last update October 16, 2001 at 03:55 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 3, 2001)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update October 3, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update October 3, 2001)] [Historical solar and geomagnetic data charts 1954-2001 (last update October 16, 2001)] Recent development The geomagnetic field was quiet to active on October 15. Solar wind speed ranged between 368 and 452 km/sec. Solar flare activity was low. Solar flux was 192.9, the planetary A index was 11 (3-hour K indices: 3432 2322, Boulder K indices: 3432 3221). Regions 9653 decayed and was spotless by early evening. Region 9655 decayed into spotless plage. Region 9658 decayed slowly and quietly. Region 9659 developed slowly and quietly. Region 9660 decayed and was spotless by early evening. Region 9661 developed new spots in several parts of the region, an isolated major flare is still possible. Regions 9662 and 9663 decayed slowly and quietly. Region 9666 decayed and was spotless by early evening. Region 9667 was quiet and stable. New region 9668 emerged briefly in the northeast quadrant near the central meridian, the region is spotless. New region 9669 rotated into view at the northeast limb. An active region has rotated into view at the southeast limb and will be numbered today. Flares and CMEs A total of 5 C class events were recorded on October 15. Region 9661 produced a C3.7 flare at 16:18 UTC, the remaining flares were all optically unaccounted. The background x-ray flux is at the class C1 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 16-17. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor and improving slowly. 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 Location region numbered no. at Area Classification Comment sunspots midnight 9650 2001.10.03 S17W82 plage 9653 2001.10.04 2 S22W64 0020 BXO now spotless 9655 2001.10.06 S22W50 plage 9657 2001.10.08 N22W23 plage 9658 2001.10.09 21 S15W09 0160 FAO spot count too high 9659 2001.10.10 4 N04W51 0040 CRO 9660 2001.10.10 1 N13W36 0020 HRX now spotless 9661 2001.10.10 16 N15E17 0720 EKI beta-gamma-delta spot count too low 9662 2001.10.11 8 N09W12 0060 CSO 9663 2001.10.11 1 S15E09 0020 HSX 9664 2001.10.12 N07W23 plage 9665 2001.10.13 S26W83 plage 9666 2001.10.14 1 S11E18 0000 AXX now spotless 9667 2001.10.14 4 N23E60 0060 CAO 9668 2001.10.15 4 N29E01 0010 BXO now spotless 9669 2001.10.15 4 N13E70 0070 CSO Total number of sunspots: 66 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.04 184.2 125.5 120.8 cycle 23 sunspot max. 2000.07 202.3 170.1 119.8 2000.09 182.1 109.7 116.3 (-2.3) 2000.10 167.4 99.4 114.5 (-1.8) 2000.11 178.8 106.8 112.7 (-1.8) 2000.12 173.6 104.4 112.0 (-0.7) 2001.01 166.6 95.6 108.7 (-3.3) 2001.02 146.6 80.6 104.1 (-4.6) 2001.03 177.7 113.5 104.8 (+0.7) 2001.04 177.7 107.7 (107.7 predicted, +2.9) 2001.05 147.1 96.6 (108.1 predicted, +0.4) 2001.06 173.0 134.0 (106.3 predicted, -1.8) 2001.07 131.3 82.2 (105.1 predicted, -1.2) 2001.08 162.9 106.8 (105.7 predicted, +0.6) 2001.09 233.2 150.7 (105.1 predicted, -0.6) 2001.10 184.7 (1) 86.5 (2) (102.3 predicted, -2.8) 1) Running average based on the daily 20:00 UT solar flux value at 2800 MHz. 2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official international sunspot number 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 noted in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]