Solar Terrestrial Activity Report [Image] Last update August 31, 2002 at 06:20 UTC. (posted late because of a local power outage) [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 30. Solar wind speed ranged between 351 and 443 km/sec. Solar flare activity was high. Solar flux was 170.2, the planetary A index was 10 (3-hour planetary K indices: 1332 3232, Boulder K indices: 3332 3221). Region 10085 was quiet and stable and is about to rotate over the southwest limb. Region 10087 changed its appearance significantly with a number of new spots emerging while some of the existing penumbrae lost some of their areal coverage. Occasional minor M class flares are possible. Region 10090 decayed losing most of its spots. The leading penumbra did, however, gain some area. Region 10092 decayed and will probably become spotless today. Region 10094 developed further and was quiet. A minor M class flare is possible as there is not much separating the negative and positive polarity areas. Region 10095 rotated fully into view. A small positive polarity field is fully embedded within the trailing negative polarity spot section. As long as this magnetic delta exists further major flares will be possible. New region 10096 rotated into view at the southeast limb. SEC/NOAA failed to number a new region which emerged due west of region 10087 in the southwest quadrant. Flares and CMEs A total of 10 C and 1 X class events was recorded on August 30. Region 10092 produced a C4.3 flare at 10:53 UTC. Region 10095 generated a major X1.5 impulsive flare (no obvious CME was observed) at 13:29, a C8.4 flare at 14:40 and a C2.8 flare at 15:34 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 August 31 and September 1. 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 S08W76 0280 HAX 10086 2002.08.22 S26W76 plage 10087 2002.08.22 29 S08W33 0230 DKC beta-gamma 10089 2002.08.24 S16W18 plage 10090 2002.08.26 13 S04W06 0070 DAO 10091 2002.08.27 N06W02 plage 10092 2002.08.27 3 S19W35 0030 BXO 10093 2002.08.29 S16E00 plage 10094 2002.08.29 9 S17E54 0160 DSO 10095 2002.08.29 24 N07E65 0450 FKI beta-gamma-delta 10096 2002.08.30 1 S14E75 0080 HAX Total number of sunspots: 80 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) 2002.08 183.8 (1) 186.7 (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]