Solar Terrestrial Activity Report [Image] Last update September 30, 2002 at 03:20 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update 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 quiet to unsettled on September 29. Solar wind speed ranged between 283 and 344 km/sec. A geomagnetic disturbance is in progress. The interplanetary magnetic field has been weakly to moderately southwards since midnight. No increase in solar wind speed has been observed so far but the disturbance is likely related to the arrival of a coronal stream. Solar flare activity was moderate. Solar flux was 138.1, the planetary A index was 6 (S.T.A.R. calculated average value based on three hour Ap indices: 7.5). Three hour interval K indices: 22112331 (planetary), 11012212 (Boulder). The background x-ray flux is at the class B7 level. Region 10125 decayed and had apparently lost the leading negative spots by midnight. The region is rotating over the southwest limb. Flare: C7.8 long duration event peaking at 08:59 UTC. Region 10129 was quiet and stable. Region 10130 decayed slowly and quietly and lost the trailing spots. Region 10132 rotated quietly out of view at the northwest limb. Region 10134 developed at a moderate pace nearly doubling its penumbral area. The magnetic observed during the previous two days disappeared. Further minor M class flares are possible. Flares: M2.6/2N at 06:39 and C9.3/1N at 14:49 UTC. Region 10135 decayed slowly and quietly and could become spotless today. New region 10136 emerged on September 28 and decayed on Sept.29 becoming spotless again by early afternoon. New region 10137 emerged on Sept.28 and developed slowly on Sept.29. Magnetograms indicate that that polarities are becoming intermixed. The region is likely to develop further. Two new regions emerged: Several spots emerged in an area due east of region 10134 and just northeast of a positive polarity penumbra (which has been an unnumbered region and mistakenly included in region 10134 since it rotated into view). The new region could actually merge with that penumbra as the positive polarity areas are quite close. Another new region emerged just west of region 10137 in the southeast quadrant. Activity is increasing at the northeast limb and a new region could soon rotate into view. This region may have been the source of an M2.1 flare at 01:50 UTC on Sept.30. Coronal mass ejections (CMEs) September 29: A partial halo CME covering most of the southern limbs and the south pole probably had a backside origin as there was no obvious front side activity at the time. Coronal holes A well placed coronal hole in the southern hemisphere was in a geoeffective position on September 26-27. Forecast The geomagnetic field is expected to be unsettled to active (possibly with a few minor storm intervals) on September 30 due to a coronal stream and quiet to active on October 1. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is good but will likely become poor today. 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 HAX group with an 10125 2002.09.18 5 S09W78 0140 DAO area of 0050 observed at midnight 10126 2002.09.19 S22W55 plage 10128 2002.09.20 N10W55 plage 10129 2002.09.22 2 N26W39 0020 AXX 10130 2002.09.22 5 N05W44 0130 DSO 10131 2002.09.22 S06W61 plage 10132 2002.09.22 7 N21W90 0100 DAO area 0060 at best early in the day 10133 2002.09.23 S27W55 plage beta-gamma actually a DAI region 10134 2002.09.24 38 N12E11 0250 EAI as the easternmost spots belong to other regions. 10135 2002.09.27 4 S25W21 0020 CRO 10136 2002.09.29 2 S27W36 0020 CSO now spotless 10137 2002.09.29 3 S16E50 0040 CSO area 0060, classification DAO at midnight Total number of sunspots: 66 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) 2002.09 177.1 (1) 203.6 (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]