Solar Terrestrial Activity Report [Image] Last update July 28, 2002 at 06:30 UTC. Only occasional updates will be posted until August 3 due to vacation. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update July 1, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update July 1, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update July 1, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update April 13, 2002)] Recent development The geomagnetic field was unsettled to active on July 27. Solar wind speed ranged between 389 and 547 km/sec. Solar flare activity was low. Solar flux was 230.8, the planetary A index was 19 (3-hour planetary K indices: 4334 4343, Boulder K indices: 3333 3233). Region 10036 appeared to be developing slowly as it began to rotate over the southwest limb. Region 10037 was quiet and stable. Region 10038 decayed slowly and quietly. Region 10039 decayed in the leading spot section and developed in the trailing spots section. There are two magnetic deltas, a strong one in the largest penumbra and one in a smaller trailing penumbra. The region could produce major flares. Region 10042 was quiet and stable. Region 10043 developed slowly and added a few new spots. Region 10044 decayed significantly in the leading spot section losing quite a bit of penumbral area. The magnetic delta structure weakened. There is still a chance of another major flare. Region 10045 decayed quietly. Region 10047 decayed into spotless plage during the first hours of the day. Region 10048 developed early in the day, then began to decay slowly. Region 10049 decayed and was spotless by midnight. Region 10050 continued to develop quickly and is capable of minor M class flaring. New region 10051 rotated into view at the southeast limb. A new region emerged in the southeast quadrant (near S18E40) near noon but was not noticed by SEC/NOAA. Another new region in the northeast quadrant (near N10E30) emerged just after noon and is developing quickly. Early on July 28 a new spotted region is rotating into view at the southeast limb. Flares and CMEs A total of 6 C class events was recorded on July 27. Region 10039 produced a C9.6 flare at 02:12, a C2.5 flare at 08:32 and a C1.7 flare at 15:12 UTC. Region 10044 generated a C5.1 flare at 04:39 UTC. Region 10044 was the source of an M2.5 flare at 00:30 UTC on July 28. There may have been a geoeffective CME associated with this flare, but LASCO images are not yet available to confirm this. July 26: A long duration major M5.3 long duration event peaking at 22:13 UTC. Its origin appear to have been in region 10044. The LDE was associated with a full halo CME. This CME will impact Earth, most likely during the latter half of July 28 or the first half of July 29, and could cause active to major geomagnetic storm conditions. 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 major storm on July 28-29. 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 10036 2002.07.15 6 S08W84 0320 DAO 10037 2002.07.17 1 N13W73 0120 HSX 10038 2002.07.21 2 N17W28 0020 HSX 10039 2002.07.22 62 S15E08 0900 FKI beta-gamma-delta 10040 2002.07.22 S19W69 plage 10041 2002.07.22 N16W45 plage 10042 2002.07.22 3 S21W29 0020 HSX 10043 2002.07.23 17 N12E00 0160 DAO 10044 2002.07.23 45 S22E03 0590 FKI beta-gamma-delta 10045 2002.07.24 16 N05W25 0160 DAI 10046 2002.07.24 N15W17 plage no images support the 10047 2002.07.25 7 N09W74 0030 CAO data provided by SEC/NOAA, the region became spotless early in the day. 10048 2002.07.26 9 N20E38 0050 CSO area too large, too many 10049 2002.07.26 10 S05W44 0030 DAO spots region is now spotless poor observation by SEC/NOAA, area was more than 0200 and more 10050 2002.07.26 13 S07E23 0090 DSO than 30 spots were seen during early evening beta-gamma 10051 2002.07.27 2 S17E66 0090 CAO Total number of sunspots: 193 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 2001.06 173.0 134.0 109.8 (+1.2) 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 (112.7 predicted, -1.9) 2002.02 205.0 107.4 (111.3 predicted, -1.4) 2002.03 179.5 98.4 (106.6 predicted, -4.7) 2002.04 189.8 120.4 (100.7 predicted, -5.9) 2002.05 178.4 120.8 (96.3 predicted, -4.4) 2002.06 148.7 88.5 (91.7 predicted, -4.6) 2002.07 165.5 (1) 145.3 (2) (86.9 predicted, -4.8) 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]