Solar Terrestrial Activity Report [Image] Last update October 29, 2002 at 02:30 UTC. Minor update posted at 11:30 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 unsettled to active on October 28. Solar wind speed ranged between 554 and 697 km/sec under the influence of a high speed coronal stream. Solar flare activity was moderate. Solar flux was 158.3, the planetary A index was 17 (STAR Ap - based on the mean of three hour ap indices: 18.2). Three hour interval K indices: 44333333 (planetary), 44332333 (Boulder). The background x-ray flux is at the class B7 level. At midnight there were 11 spotted regions on the visible disk, 3 of which have not yet been numbered. A total of 16 C and 1 M class events were recorded during the day. Region 10162 developed significantly in the northern and western part of the trailing spot section. The magnetic delta structure became larger and there is now a real possibility of a major flare any time before the region rotates over the northwest limb on October 30-31. Flares: C1.6 at 00:26, C2.1 at 09:28, C1.4 at 10:28, M1.7/1N at 12:05, C1.1 at 13:58, C2.5 at 14:18, C1.2 at 16:04, C1.0 at 16:34, C2.8 at 18:30, C5.0 at 19:03, C2.3 at 19:47, C1.7 at 21:42, C1.1 at 22:58 and C1.0 at 23:25 UTC. Region 10165 decayed slowly and quietly. Region 10167 was quiet and stable. Region 10169 appears to be two separate regions. The two northern penumbrae make up one region, the southernmost of these spots decayed slowly on Oct.28. I have split the southern spot section off into region S13, see below. Region 10170 decayed and could become spotless today. Region 10171 was quiet and stable. Region 10172 decayed and could become spotless today or tomorrow. New region 10173 emerged in the southwest quadrant late on Oct.27 and has developed slowly since then. Spotted regions not yet numbered: [S13] A new region emerged just south of region 10169 on October 27 and has been developing slowly since then. The inversion line is running east-west and further development is likely. Location at midnight: S23E70. [S14] A new region rotated into view at the southeast limb on October 28 and is developing slowly. Location at midnight: S26E69. [S15] A new region emerged near the northeast limb on October 28. Location at midnight: N13E66. Comment added at 11:30 UTC on October 29: Some changes observed since midnight: A new region is rotating into view at the northeast limb. Currently only a large penumbra is visible at N14E87. Region 10173 has developed with the leading penumbra increasing significantly in size. Polarities appear to be mixed as the region approaches the southwest limb. Region S14 has seen a small spot in its northwestern part develop penumbra and the classification has changed to DAO. Region 10162 has lost a significant amount of penumbra in the trailing spot section and several small spots have disappeared. This decay appears to have begun following an M1.1 flare at 03:20 UTC. Coronal mass ejections (CMEs) October 27: No CMEs of interest were observed until late in the day. A C4.0 event caused by a filament eruption in the northeast quadrant was associated with a CME off the east limb. The CME was first visible in LASCO C2 images at 22:26 UTC. A full halo CME was visible by midnight, this impressive CME was observed with most of the material over the southeast quadrant and may have the same source (a large region several days behind the southeast limb) as numerous halo CMEs observed October 24-26. October 28: No significant CMEs were observed. Coronal holes A trans equatorial coronal hole will rotate into a geoeffective position on October 31-November 1. Forecast The geomagnetic field is expected to be quiet to active on October 29 and quiet to unsettled on October 30-31. A coronal stream is expected to begin on November 3 and will likely cause unsettled to minor storm conditions. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor to 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 10162 2002.10.17 39 56 N25W59 0840 FKC beta-gamma-delta 10164 2002.10.20 N11W52 plage 10165 2002.10.20 2 2 N21W34 0130 HAX 10166 2002.10.23 S06W57 plage 10167 2002.10.23 2 2 N17E10 0040 HSX location at midnight: S18E20, classification 10169 2002.10.24 9 3 S20E21 0050 DAO HSX then, the southern spot section is region S13 area was 0010 at 10170 2002.10.25 3 2 S12E24 0030 CAO midnight, classification AXX 10171 2002.10.25 3 1 N10E39 0070 HAX 10172 2002.10.27 2 2 S17E44 0020 HSX 10173 2002.10.28 3 5 S17W69 0050 CSO formerly region S11 S10 emerged on N08E08 plage 2002.10.26 S12 emerged on S12W43 plage 2002.10.27 S13 emerged on 9 S22E22 0030 CRO beta-gamma 2002.10.27 S14 visible on 2 S26E69 0020 CAO 2002.10.28 S15 emerged on 2 N13E66 0000 AXX 2002.10.28 Total spot count: 63 86 SSN: 143 196 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) 2002.10 167.0 (1) 138.3 (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]