Solar Terrestrial Activity Report [Image] Last update August 20, 2002 at 03:25 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 unsettled to minor storm on August 19. Solar wind speed ranged between 450 and 567 km/sec, slowly decreasing all day. Solar flare activity was moderate. Solar flux was 237.0, the planetary A index was 27 (3-hour planetary K indices: 4454 4344, Boulder K indices: 4353 3433). Region 10063 rotated quietly over the northwest limb. Region 10066 decayed further and was left with only two small spots at the end of the day. The region could become spotless later today or tomorrow. Region 10067 decayed early in the day losing most of its spots including all trailing spots. Some slow development was noted later in the day in the leader spots. Region 10068 decayed and was spotless before noon. Region 10069 did not change much overall, however, some decay was observed in the southern section of the region. There is a strong magnetic delta in the leading part of the enormous penumbra. There is still a good chance of a major X class proton flare. Region 10076 decayed slowly and quietly and could become spotless within a couple of days. Region 10079 decayed quickly as the opposing polarity areas drifted apart. Region 10080 decayed further and lost most of its small spots. Region 10083 was quiet and stable, as was region 10084. New region 10085 rotated into view revealing a large penumbra. Flares and CMEs A total of 7 C and 2 M class events was recorded on August 19. Region 10069 produced an M2.0 flare at 10:34, a C1.9 flare at 11:24, a C3.5 flare at 13:01, a C9.5 flare at 14:46 and an M3.1/1B flare at 21:02 UTC. Region 10069 appears to have been the source of a major M5.0 flare at 01:40, an M1.4 flare at 01:49 and an M1.4 flare at 02:57 on August 20. A CME was observed after the major flare, but I don't know yet if the CME is geoeffective. August 18: Region 10069 produced an M2.2/1B flare (associated with a weak type II sweep) at 21:25 UTC. A CME was observed towards the end of the day in LASCO C3 images. Most of the ejected material was seen below the south pole, however, there appears to be a weak expanding front all around the disk. The CME will likely impact Earth but only a minor disturbance is likely on August 21-22 The background x-ray flux is at the class C1 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to active on August 20-22. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 10063 2002.08.06 1 N17W88 0060 HSX only 2 spots observed 10066 2002.08.09 5 N14W60 0060 DAO at the end of the day with an area of 0030 10067 2002.08.10 9 N10W48 0090 DAO region was spotless 10068 2002.08.10 2 S08W53 0030 BXO before noon, odd "observation" by SEC/NOAA 10069 2002.08.11 60 S08W30 1990 EKC beta-gamma-delta 10075 2002.08.12 S11W63 plage 10076 2002.08.12 1 N12W15 0020 HSX 10077 2002.08.13 S18W17 plage 10078 2002.08.14 S14W79 plage another strange observation from 10079 2002.08.14 38 S22W08 0430 EAI SEC/NOAA, area was less than 0200 by midnight 10080 2002.08.14 10 N16E03 0130 DAO too many spots and too large area 10081 2002.08.16 N18E21 plage 10082 2002.08.17 N20W20 plage 10083 2002.08.17 5 S18E36 0050 DAO 10084 2002.08.18 1 S16E50 0100 HAX 10085 2002.08.19 5 S11E69 0460 DHO Total number of sunspots: 137 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) 2002.08 180.1 (1) 128.1 (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]