Solar Terrestrial Activity Report [Image] Last update August 29, 2002 at 03:45 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 unsettled on August 28. Solar wind speed ranged between 377 and 550 km/sec, generally increasing all day under the influence of a weak coronal stream. Solar flare activity was moderate. Solar flux was 163.2, the planetary A index was 10 (3-hour planetary K indices: 3322 2333, Boulder K indices: 2222 3323). Region 10083 decayed quickly and had only a couple of small spots by late afternoon, the region is rotating quietly over the southwest limb. Region 10084 decayed and could become spotless today. Region 10085 decayed slowly and quietly. Region 10087 began to decay and lost a significant amount of penumbral area in the southern section. There is still a weak magnetic delta structure in the central western part of the region. Occasional minor M class flares are possible. Region 10090 was quiet and stable. Region 10091 decayed into spotless plage. Region 10092 was quiet and stable. A region which emerged southeast of region 10090 on August 27 was, incredibly, again not noticed by SEC/NOAA. The region is decaying and could soon become spotless. Early on August 29 a new region is rotating into view at the northeast limb. So far only a few spots are visible. This region has been the source of a strong surge in solar activity and has produced 4 M class flares during the last 10 hours. Further M class flares are very likely and there is a good chance of a major flare as well. The corona is very hot above this region. Flares and CMEs A total of 12 C and 3 M class events was recorded on August 28. Region 10083 produced a C5.7 flare at 11:00 and a C4.4 flare at 17:48 UTC. The region at the northeast limb was the source of an M1.3 flare at 16:58, an M4.6 flare (associated with a weak type II and a strong type IV radio sweep as well as a fairly narrow CME off the northeast limb) at 18:59 and an M1.1 flare at 21:45 UTC. An M1.6 flare at 02:53 UTC on August 29 was noted from the region at the northeast limb. August 26: Region 10083 was the source of a long duration M1.8 event peaking at 01:00 UTC. A CME was observed mainly off the west limb, however, a faint halo could be observed all around the disk. A minor geomagnetic disturbance is possible on August 29. The background x-ray flux is at the class C2-C3 level. Coronal holes A coronal hole in the southeast quadrant will likely rotate into a geoeffective position on August 30. Forecast The geomagnetic field is expected to be quiet to active on August 29 and quiet to unsettled on August 30-31. 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) Solar Date Actual Location region numbered no. at Area Classification Comment sunspots midnight area too large, was 10083 2002.08.17 1 S18W84 0070 HSX about 0020 by midnight area too large, 10084 2002.08.18 3 S17W66 0060 CAO near 0020 at midnight 10085 2002.08.19 5 S08W50 0450 DKO area too large 10086 2002.08.22 S26W50 plage 10087 2002.08.22 13 S08W07 0450 DKC beta-gamma-delta area too large 10089 2002.08.24 S16E08 plage 10090 2002.08.26 3 S04E20 0020 CSO 10091 2002.08.27 N06E24 plage 10092 2002.08.27 2 S19W09 0020 HSX Total number of sunspots: 27 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) 2002.08 184.8 (1) 177.1 (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]