Solar Terrestrial Activity Report [Image] Last update October 25, 2002 at 04:10 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 active to major storm on October 24. Solar wind speed ranged between 446 and 754 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 160.3, the planetary A index was 47 (STAR Ap - based on the mean of three hour ap indices: 48.6). Three hour interval K indices: 45566554 (planetary), 44455544 (Boulder). The background x-ray flux is at the class B5 level. At midnight there were 6 spotted regions on the visible disk. A total of 5 C class events were recorded during the day. Region 10158 rotated quietly out of view at the southwest limb. Region 10160 was spotless all day in all available images. Region 10162 decayed further in the trailing spot section. Penumbral area was lost in the easternmost spots and in the northern section of the trailing spots. The magnetic delta in the northernmost central penumbra weakened and could soon disappear. M class flares are possible. Flares: C1.0 at 08:18, C7.4/1N at 18:10, C1.7 at 21:59 and C1.2 at 22:10 UTC. A weak type IV radio sweep was recorded along with the C7 flare. Region 10164 reemerged early in the day with several small spots. Region 10165 developed slowly with several small spots emerging and the large penumbra elongating. Region 10167 was quiet and stable. New region 10168 emerged with a single spot. This was formerly region S06 which was observed with spots on October 19. New region 10169 rotated into view at the southeast limb. Coronal mass ejections (CMEs) October 22-23: No obviously geoeffective CMEs were observed. October 24: A full halo CME was observed at 08:50 UTC in LASCO images. With no obvious front side source it is likely that this CME had a source about 5-6 days behind the southwest limb. Another full halo CME was first visible in LASCO C2 images at 21:26 UTC. Again no obvious front side activity could be associated with this CME. Its likely origin is several days behind the west limb. Coronal holes A large and well defined coronal hole in the southern hemisphere was in a geoeffective position on October 21-25. Forecast The geomagnetic field is expected to be active to major storm on October 25, unsettled to minor storm on October 26 and quiet to active on October 27-28. 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) 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 spotless, location 10158 2002.10.12 3 S06W88 0080 DAO was S09W85. SEC location identical to that of S03 10159 2002.10.13 S15W72 plage 10160 2002.10.14 4 S18W83 0010 BXO spotless all day 10162 2002.10.17 44 57 N26W04 0990 FKC beta-gamma-delta 10163 2002.10.18 S21W88 plage 10164 2002.10.20 8 5 N11E01 0020 BXO 10165 2002.10.20 6 13 N20E18 0210 CAO beta-gamma 10166 2002.10.23 S06W05 plage 10167 2002.10.23 1 1 N17E64 0040 HSX classification should be HSX, 10168 2002.10.24 1 1 N24W64 0020 HRX formerly region S06 which was observed first on October 19 10169 2002.10.24 2 2 N17E64 0040 HSX S03 emerged on S06W88 rotated out of view 2002.10.15 Total spot count: 69 79 SSN: 149 139 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) 2002.10 167.9 (1) 120.3 (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]