Solar Terrestrial Activity Report [Image] Last update August 19, 2002 at 03:30 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 minor storm on August 18. Solar wind speed ranged between 381 and 648 km/sec. A moderate solar wind shock was observed at 18:15 UTC at SOHO. Solar wind speed increased abruptly from 420 to 630 km/sec. The arrival of this disturbance, caused by a halo CME observed on August 16, occurred several hours later than expected. Solar flare activity was moderate. Solar flux was 241.0, the planetary A index was 18 (3-hour planetary K indices: 4323 3245, Boulder K indices: 3322 3225). Region 10063 was quiet and stable. Region 10066 decayed slowly and quietly. Region 10067 decayed very quickly and quietly. If the current rate of decay continues, the region will become spotless later today. Region 10068 decayed further and had only a single small spot left by the end of the day, the region could become spotless today. Region 10069 did not change much. Some increase in penumbral coverage was observed in the western part, on the other hand, some penumbral decrease was noted in the southernmost part of the region. There is still a good chance of a major X class proton flare occurring. Region 10076 was quiet and stable. Region 10079 developed slowly and could produce minor M class flares. Region 10080 decayed slowly and quietly. Region 10081 decayed and was spotless by the end of the day. Region 10082 decayed and was spotless by early evening. Region 10083 was quiet and stable. New region 10084 rotated into view at the southeast limb. Early on August 19 a fairly large penumbra is rotating into view at the southeast limb. Flares and CMEs A total of 12 C and 3 M class events was recorded on August 18. Region 10069 produced a C3.3 flare at 00:08, a C3.2 flare at 01:49, a C8.4/1F flare at 03:34, a C8.0 flare at 07:36, an M2.3 flare at 10:05, a C4.9 flare at 13:50, an M1.9 flare at 14:39, a C8.7 flare at 20:24 and an M2.2/1B flare (associated with a weak type II sweep) at 21:25 UTC. Region 10079 generated a C4.5 flare at 05:58 and a C4.5 flare at 19:56 UTC. Region 10083 was the source of a C6.0 flare at 16:50 UTC. No CMEs appeared to have been associated with any of the flares. The only two CMEs appeared to be one directed off the southwest limb early in the day and another one late in the day where most of the ejected material was observed below the south pole. The background x-ray flux is at the class C1-C2 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be unsettled to minor storm on August 19 and quiet to active on August 20-21. 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 N18W75 0080 HAX 10065 2002.08.08 S07W78 plage 10066 2002.08.09 11 N14W48 0060 DAO 10067 2002.08.10 33 N12W34 0080 EAO area too large, was near 0040 10068 2002.08.10 1 S08W39 0020 HSX area 0010 at midnight 10069 2002.08.11 74 S08W18 1960 EKC beta-gamma-delta 10074 2002.08.12 N24W79 plage 10075 2002.08.12 S11W50 plage 10076 2002.08.12 2 N12W02 0020 CSO 10077 2002.08.13 S18W04 plage 10078 2002.08.14 S14W66 plage 10079 2002.08.14 38 S22E04 0310 EAC 10080 2002.08.14 13 N16E17 0110 DAO 10081 2002.08.16 2 N18E34 0010 AXX now spotless 10082 2002.08.17 4 N20W07 0010 BXO now spotless 10083 2002.08.17 8 S18E52 0080 DSO 10084 2002.08.18 1 S16E64 0110 HAX Total number of sunspots: 188 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) 2002.08 177.0 (1) 120.2 (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]