Solar Terrestrial Activity Report [Image] Last update October 21, 2002 at 03:20 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, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update October, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update October 2, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update October 13, 2002)] Recent activity The geomagnetic field was quiet to unsettled on October 20. Solar wind speed ranged between 558 and 763 km/sec under the influence of a high speed coronal stream. Solar flare activity was moderate. Solar flux was 180.3, the planetary A index was 10 (STAR Ap - based on the mean of three hour ap indices: 11.3). Three hour interval K indices: 23123333 (planetary), 23223223 (Boulder). The background x-ray flux is at the class C1 level. At midnight there were 9 spotted regions on the visible disk, 1 of which has not yet been numbered. A total of 13 C and 4 M class events were recorded during the day. Region 10145 rotated quietly out of view at the northwest limb early on Oct.21. Region 10149 decayed quickly and lost about half of its penumbral area. The region will rotate over the northwest limb late today. Region 10154 decayed and was spotless by early evening. Flares: C6.9 at 05:31, C6.6 at 14:13 and C2.6 at 18:05 UTC. Region 10158 was quiet and stable. Please observe that SEC has included the spots of S03 (see below) in this region. Region 10159 decayed quickly in the leading spot section but did gain a couple of trailing spots. Region 10160 decayed in the trailing spot section. Some minor development occurred in the leading spots. The positive polarity area, which emerged one day earlier on the northern edge of the leading negative polarity area, weakened slowly. Flares: C7.5/1N at 02:23, M1.2/1N at 05:14 and M1.8/1B at 14:28 UTC. Region 10162 developed quickly in the trailing spot section adding a large amount of penumbral area. Major flares are possible. Flares: M1.8/1F long duration event peaking at 00:45, M1.5/2N at 03:39, C3.6 at 06:14, C2.0/1F at 09:03, C5.9 at 14:02 and C3.1 at 19:21 UTC. New region 10164 emerged near the northeast limb on October 19 and was numbered on Oct. 20. Only slow development has been observed so far. New region 10165 rotated into view on October 19 and was numbered on Oct. 20. No change has been observed over the last day. Spotted regions which have not yet been numbered: 1. [S03] A region emerged in the southeast quadrant northeast of region 10158 on October 15. The region developed slowly until October 18. Slow decay was observed on October 19. On October 20 the region decayed quickly and could soon become spotless. Location at midnight: S05W30. Flare: C2.4 at 09:15 UTC. Coronal mass ejections (CMEs) October 18-20: No obviously geoeffective CMEs were observed. Coronal holes A large coronal hole in the southern hemisphere will be in a geoeffective position on October 21-24 and is likely to cause unsettled to minor geomagnetic storm conditions on October 24-27. Forecast The geomagnetic field is expected to be quiet to unsettled on October 21-23. 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) Data for all numbered solar regions according to the Solar Region Summary provided by SEC/NOAA. Comments are my own, as is the STAR spot count (spots observed at or just prior to midnight) and data for regions not numbered by SEC or where SEC has observed no spots. Solar Date SEC STAR Location region numbered spot spot at AreaClassification Comment countcount midnight 10145 2002.10.08 1 1 N11W85 0060 HSX 10148 2002.10.09 S21W74 plage 10149 2002.10.09 9 4 N14W75 0250 DSO area was approx. 0150 at midnight 10153 2002.10.10 S05W83 plage 10154 2002.10.10 1 S14W62 0010 AXX now spotless 10157 2002.10.12 N15W58 plage SEC spot count includes those of 10158 2002.10.12 10 2 S07W32 0100 DSO region S03. This is a CSO group. Position was S10W32 at midnight. 10159 2002.10.13 6 6 S12W22 0060 DSO 10160 2002.10.14 28 22 S21W26 0130 EAO beta-gamma 10161 2002.10.15 N06W65 plage 10162 2002.10.17 32 27 N26E46 0960 FHI beta-gamma-delta 10163 2002.10.18 S21W36 plage classification should 10164 2002.10.20 1 1 N11E54 0020 AXX be HRX formerly region S07 10165 2002.10.20 1 1 N20E71 0180 HSX formerly region S08 S03 emerged on 5 S05W30 0020 DRO 2002.10.15 S06 emerged on N24W10 plage 2002.10.19 Total spot count: 89 69 SSN: 179 159 Monthly solar data Average Month solar International sunspot Smoothed sunspot flux at number number Earth 2000.04 184.2 125.5 120.8 cycle 23 sunspot max. 2000.07 202.3 170.1 119.8 2001.09 233.2 150.7 114.1 (+0.5) 2001.10 207.6 125.5 114.0 (-0.1) 2001.11 210.6 106.5 115.5 (+1.5) 2001.12 235.1 132.2 114.6 (-0.9) 2002.01 226.6 114.1 113.5 (-1.1) 2002.02 205.0 107.4 114.7 (+1.2) 2002.03 179.5 98.4 113.4 (-1.3) 2002.04 189.8 120.7 (109.7 predicted, -3.7) 2002.05 178.4 120.8 (105.9 predicted, -3.8) 2002.06 148.7 88.3 (101.4 predicted, -4.5) 2002.07 173.5 99.9 (96.5 predicted, -4.9) 2002.08 183.6 116.4 (92.5 predicted, -4.0) 2002.09 175.8 109.3 (88.7 predicted, -3.8) 2002.10 167.7 (1) 103.0 (2) (84.6 predicted, -4.1) 1) Running average based on the daily 20:00 UT observed 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 25-45% 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]