Solar Terrestrial Activity Report [Image] Last update October 3, 2002 at 04:20 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 August 16, 2002)] Recent activity The geomagnetic field was unsettled to severe storm on October 2. Solar wind speed ranged between 351 and 540 km/sec. The interplanetary magnetic field was moderately to strongly southwards during most of the first half of the day and weakly southwards for most of the second half. A solar wind shock was observed at SOHO at 21:58 UTC with a sudden increase in solar wind speed from 460 to 480 km/sec. This shock was likely related to the full halo CME observed early on September 30. After the shock the IMF was moderately strongly southwards, but has now swung northwards. Solar flare activity was low. Solar flux was 135.8, the planetary A index was 44 (S.T.A.R. calculated average value based on three hour Ap indices: 49.8). Three hour interval K indices: 67644334 (planetary), 66533324 (Boulder). The background x-ray flux is at the class B6 level. Region 10130 decayed slowly as it rotated quietly over the northwest limb. Region 10134 was quiet and decayed further with nearly half of the penumbral area in the trailing spot section disappearing. Region 10137 developed moderately quickly during the latter half of the day when negative polarity flux emerged on the northern side of the trailing positive polarity area. A magnetic delta structure formed during the last hours of the day. Frequent flaring is likely to continue as long as the current situation in the trailing spot section persists. Flares: C1.6 at 12:18, C1.1 at 16:56, C1.5 at 18:21, C2.0 at 18:39, C4.2 at 19:17, C2.0 at 21:18, C1.6 at 21:46 and C5.5 at 22:41 UTC. Region 10138 was quiet and stable. New region 10139 rotated into view at the northwest limb. Two new regions emerged in the southeast quadrant and were visible before noon. The largest of them was located near S16E30 at midnight while the other one was at S11E14. An M2.1/1N flare at 02:21 UTC on October 3 had its origin in region 10137. Coronal mass ejections (CMEs) October 2: A couple of partial halo CMEs were observed during the day. One of them may have been associated with an erupting filament while the other one appears to have had a backside origin. Neither of the CMEs are likely to be geoeffective. Coronal holes A coronal hole in the southern hemisphere will rotate into a geoeffective position on October 4-6. Forecast The geomagnetic field is expected to be quiet to major storm on October 3 and quiet to unsettled on October 4-5. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is useless. 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 10129 2002.09.22 N28W79 plage 10130 2002.09.22 1 N04W87 0070 HSX 10134 2002.09.24 13 N13W29 0350 DKI area was near 0270 at midnight 10135 2002.09.27 S23W62 plage 10136 2002.09.29 S31W74 plage 10137 2002.09.29 29 S18E08 0310 DKI beta-gamma-delta 10138 2002.10.01 2 N10W25 0020 HSX 10139 2002.10.02 4 N14E72 0120 DSO xxx emerged (1) S16E30 0010 HRX 2002.10.02 xxx emerged (1) S11E14 0000 AXX 2002.10.02 Total number of sunspots: 49 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 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) 2002.04 189.8 120.4 (109.7 predicted, -3.7) 2002.05 178.4 120.8 (105.9 predicted, -3.8) 2002.06 148.7 88.5 (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) 2002.10 137.8 (1) 6.6 (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]