Solar Terrestrial Activity Report [Image] Last update October 1, 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 September 3, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update September 3, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update September 3, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update August 16, 2002)] Recent activity The geomagnetic field was unsettled to major storm on September 30. Solar wind speed ranged between 289 and 381 km/sec. The disturbance that was in progress early in the day was replaced by a significantly stronger disturbance when a solar wind shock was observed at ACE at 07:22 UTC. Solar wind speed increased abruptly from 300 to 330 km/sec. This low speed CME suggests an origin data at the sun on September 25 or 26. The interplanetary magnetic field was at times strongly southwards after the arrival of the solar storm. Solar flare activity was moderate. Solar flux was 139.7, the planetary A index was 26 (S.T.A.R. calculated average value based on three hour Ap indices: 27.9). Three hour interval K indices: 33446434 (planetary), 23445434 (Boulder). The background x-ray flux is at the class B5 level. Region 10125 rotated quietly out of view at the southwest limb. Region 10129 decayed slowly and quietly. Region 10130 decayed slowly and quietly. Region 10134 developed slowly in the leading and trailing spot section. Decay was observed in the central and southeastern spots. There is significantly less polarity intermixing compared to one day ago and the region's activity level has decreased a lot. Further minor M class flares are possible. Flares: M2.1/1B at 01:50, C1.6 at 03:12, C2.1 at 04:22, C5.3/1F at 05:31, C5.1 at 05:45, C3.2 at 06:43, C2.1 at 08:09, C2.2 at 09:20, C2.2 at 11:42, C2.3 at 17:20 and C2.2 at 19:01 UTC. Region 10135 decayed and was spotless by early afternoon. Region 10137 developed at a moderate pace. There is little separating the positive and negative polarity areas in the trailing spot section. A minor M class flare is possible. Coronal mass ejections (CMEs) September 30: A faint full halo CME was observed in LASCO C2 and C3 images following a filament eruption at the center of the solar disk. This eruption began at approximately 01:25 UTC. The CME will likely impact Earth on October 3, possibly as early as late on October 2. A large filament mainly in the southwestern quadrant erupted during the early morning as well and may have produced a partial halo CME. Coronal holes A moderately large coronal hole in the southern hemisphere will rotate into a geoeffective position on October 5-6. Forecast The geomagnetic field is expected to be quiet to minor storm on October 1 and quiet to unsettled on October 2. Unsettled to minor storm is likely on October 3. 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) Solar Date Actual Location region numbered no. at Area Classification Comment sunspots midnight 10125 2002.09.18 1 S10W89 0050 HSX 10126 2002.09.19 S22W68 plage 10128 2002.09.20 N10W68 plage 10129 2002.09.22 2 N28W53 0020 BXO 10130 2002.09.22 2 N04W59 0100 HSX 10131 2002.09.22 S06W74 plage 10133 2002.09.23 S27W68 plage beta-gamma 10134 2002.09.24 23 N13W02 0270 DAI the southeastern penumbra is a separate region 10135 2002.09.27 2 S23W36 0020 BXO now spotless 10136 2002.09.29 S27W49 plage beta-gamma 10137 2002.09.29 4 S17E36 0070 CSO area 0100, classification DAO at midnight, 15 spots observed then Total number of sunspots: 34 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 2001.08 162.9 106.4 113.6 (+1.8) 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 (113.2 predicted, -1.5) 2002.04 189.8 120.4 (108.7 predicted, -4.5) 2002.05 178.4 120.8 (104.2 predicted, -4.5) 2002.06 148.7 88.5 (99.7 predicted, -4.5) 2002.07 173.5 99.9 (94.9 predicted, -4.8) 2002.08 183.6 116.4 (90.8 predicted, -4.1) 2002.09 175.8 (1) 206.8 (2) (87.1 predicted, -3.7) 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]