Solar Terrestrial Activity Report [Image] Last update October 20, 2002 at 03:30 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 quiet to unsettled on October 19. Solar wind speed ranged between 588 and 739 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 179.5, the planetary A index was 11 (STAR Ap - based on the mean of three hour ap indices: 12.3). Three hour interval K indices: 33222333 (planetary), 22323333 (Boulder). The background x-ray flux is at the class C1 level. At midnight there were 11 spotted regions on the visible disk, 4 of which has not yet been numbered. A total of 12 C class events were recorded during the day. Region 10145 was quiet and stable. Region 10148 decayed further and was spotless by late evening. Region 10149 decayed slowly. Flare: C7.9/1F at 23:01 UTC. Region 10154 decayed and lost all trailing spots. Flare: C5.0 at 21:16 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 slowly and quietly losing penumbral area as the main penumbra split into 3 smaller penumbrae. Region 10160 decayed in the trailing and intermediate spot sections losing spots and penumbral area. Quick development was observed in the leading spot section during the latter half of the day. A positive polarity area emerged near the leading negative polarity area and polarities are currently intermixed. If development continues minor M class flares will soon become possible. Flares: C1.7 at 13:49 and C1.5 at 17:58 UTC. This region was the source of a C7.5 flare at 02:23 on October 20. Region 10162 developed moderate quickly in the trailing spot section. There is a large and strong negative polarity area in the trailing spot section, however, several small areas of positive polarity can be observed bordering the negative polarity area. Major flares are possible. Flares: C2.9 at 02:17, C2.3 at 04:25, C1.7 at 10:13, C5.0 at 18:28 and C5.9 at 20:20 UTC. This region produced an M1.9 flare at 00:45 UTC on October 20 as well. Spotted regions which have not yet been numbered: 1. [S03] A new region emerged in the southeast quadrant northeast of region 10158 on October 15. The region developed slowly until October 18 and has been decaying slowly since early on October 19. The region simplified during the day but there is still a chance of a minor M class flare. Location at midnight: S05W16. Flare: C7.2/1F at 01:22 and C2.7 at 10:55 UTC. 2. [S06] A new region emerged in the northeast quadrant near the central meridian on October 19. Location at midnight: N24E03. 3. [S07] A new region emerged near the northeast limb on October 19. The single spot was observed in an area of bright plage. Further development is possible. Location at midnight: N11E67. 4. [S08] A new region rotated into view at the northeast limb. Location at midnight: N20E84. Coronal mass ejections (CMEs) October 17-19: No obviously geoeffective CMEs were observed. Coronal holes A large coronal hole in the southern hemisphere will rotate into a geoeffective position on October 22-24 and is likely to cause unsettled to minor geomagnetic storm conditions on October 25-27. Forecast The geomagnetic field is expected to be quiet to unsettled on October 20-22. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 N12W72 0070 HSX 10148 2002.10.09 1 S21W61 0010 AXX now spotless The southern and northern spot sections 10149 2002.10.09 14 14 N14W62 0290 DAO appear to be 2 separate bipolar regions, each without intermixed polarities. 10151 2002.10.09 S14W80 plage 10153 2002.10.10 S05W70 plage 10154 2002.10.10 1 1 S14W48 0020 HSX 10157 2002.10.12 N15W45 plage SEC spot count includes those of 10158 2002.10.12 17 1 S07W18 0120 DSO region S03. This is an HSX group. Position was S10W19 at midnight. 10159 2002.10.13 8 8 S12W08 0100 DAO 10160 2002.10.14 18 30 S22W12 0110 EAO beta-gamma 10161 2002.10.15 N06W52 plage 10162 2002.10.17 16 31 N26E59 0890 FKI beta-gamma-delta 10163 2002.10.18 S21W23 plage S01 emerged on N19W60 plage 2002.10.14 S03 emerged on 15 S05W16 0110 DSO beta-gamma 2002.10.15 S06 emerged on 2 N24E03 0000 AXX 2002.10.19 S07 emerged on 1 N11E67 0010 AXX 2002.10.19 S08 visible on 1 N20E84 0130 HSX 2002.10.19 Total spot count: 76 105 SSN: 156 215 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) 2002.10 167.1 (1) 97.2 (2) (84.6 predicted, -4.1) 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 25-45% 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]