Solar Terrestrial Activity Report [Image] Last update September 1, 2002 at 02:50 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update August 7, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update August 7, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update August 7, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update August 16, 2002)] Recent development The geomagnetic field was quiet to slightly active on August 31. Solar wind speed ranged between 320 and 379 km/sec. Solar flare activity was low. Solar flux was estimated at 180, the planetary A index was 13 (3-hour planetary K indices: 2233 4232, Boulder K indices: 2234 3213). Region 10085 rotated quietly over the southwest limb. Region 10087 decayed and lost several spots in the southern section. Occasional minor M class flares are possible. Region 10090 decayed slowly and quietly. Region 10094 was mostly unchanged and quiet. Region 10095 developed moderately quickly adding penumbral area in all parts of the region. A new magnetic delta structure could be forming in a central penumbra. There is still a delta inside the main trailing penumbra. Major flares are possible. Region 10096 was mostly unchanged and quiet. New region 10097 emerged in the northeast quadrant. New region 10098 rotated into view at the southeast limb. Early on September 1 another two spotted regions are rotating into view, one at the southeast limb, another at the northeast limb. Flares and CMEs A total of 11 C class events was recorded on August 31. Region 10095 produced a C3.0 flare at 13:32, a C3.8 flare at 15:29, a C8.8 flare at 16:19 and a C9.1 flare at 19:56 UTC. The background x-ray flux is at the class C1 level. Coronal holes A coronal hole in the southern hemisphere was in a geoeffective position on August 30. Forecast The geomagnetic field is expected to be quiet to unsettled on September 1, perhaps with a few active intervals. On September 2 a coronal stream could begin to influence the field and cause unsettled to active conditions. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to 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 10085 2002.08.19 1 S08W89 0180 HHX 10086 2002.08.22 S26W89 plage 10087 2002.08.22 23 S08W47 0300 DKC beta-gamma 10089 2002.08.24 S16W31 plage 10090 2002.08.26 8 S04W20 0060 DAO 10091 2002.08.27 N06W15 plage 10092 2002.08.27 S19W48 plage 10093 2002.08.29 S16W13 plage 10094 2002.08.29 5 S17E40 0200 DSO 10095 2002.08.29 28 N07E51 0810 FKC beta-gamma-delta 10096 2002.08.30 3 S14E62 0140 DAO 10097 2002.08.31 3 N13E36 0020 DRO 10098 2002.08.31 2 S10E76 0030 AXX Total number of sunspots: 73 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 2001.07 131.3 81.8 111.7 (+1.9) 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 (114.0 predicted, -0.5) 2002.03 179.5 98.4 (110.3 predicted, -3.7) 2002.04 189.8 120.4 (104.5 predicted, -5.8) 2002.05 178.4 120.8 (100.0 predicted, -4.5) 2002.06 148.7 88.5 (95.5 predicted, -4.5) 2002.07 173.5 99.9 (90.6 predicted, -4.9) 2002.08 183.6 (1) 191.6 (2) (86.6 predicted, -4.0) 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]