Solar Terrestrial Activity Report [Image] Last update August 28, 2002 at 03:05 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 mostly unsettled on August 27 with a single active interval 03-06h UTC. Solar wind speed ranged between 359 and 450 km/sec. Solar flare activity was low. Solar flux was 161.4, the planetary A index was 15 (3-hour planetary K indices: 3433 3333, Boulder K indices: 3422 2423). Region 10083 did not change much and has a small magnetic delta structure inside the only penumbra. Region 10084 decayed slowly and quietly. Region 10085 decayed further losing a quarter of its penumbral area. Occasional minor M class flares are possible. Region 10087 developed slowly and was mostly quiet. The large penumbra is splitting into two but there is a magnetic delta structure in the new southern penumbra. Minor M class flares are possible. Region 10088 was quiet and is rotating over the southwest limb. Region 10090 was quiet and stable. New region 10091 emerged in the northeast quadrant, while new region 10092 emerged in the southeast quadrant near the central meridian. Both new regions are simple and could soon become spotless again. Flares and CMEs A total of 6 C class events was recorded on August 27. None of the flares, including an impulsive C9.0 flare at 12:29, were optically correlated. 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 B8 level. Coronal holes A coronal hole in the southeast quadrant will likely rotate into a geoeffective position on September 1. Forecast The geomagnetic field is expected to be quiet to unsettled on August 28 and quiet to active on August 29. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor to 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 10081 2002.08.16 N18W83 plage 10083 2002.08.17 2 S18W71 0100 CAO beta-delta 10084 2002.08.18 6 S17W53 0040 DAO 10085 2002.08.19 18 S08W37 0380 DKO 10086 2002.08.22 S26W37 plage 10087 2002.08.22 19 S08E06 0420 DKO beta-gamma-delta 10088 2002.08.23 1 S22W83 0090 HSX 10089 2002.08.24 S16E21 plage 10090 2002.08.26 2 S04E33 0020 HRX 10091 2002.08.27 3 N06E37 0010 AXX 10092 2002.08.27 2 S19E04 0010 AXX Total number of sunspots: 53 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) 2002.08 185.6 (1) 174.3 (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]