Solar Terrestrial Activity Report [Image] Last update July 27, 2002 at 06:10 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 26. Solar wind speed ranged between 390 and 475 km/sec. Solar flare activity was high. Solar flux was 241.5, the planetary A index was 17 (3-hour planetary K indices: 4334 3343, Boulder K indices: 3334 3333). Region 10036 continued to decay quickly and at the end of the day only a few, small trailing spots could be observed outside of the large leading penumbra. Region 10037 was quiet and stable. Region 10038 decayed slowly and quietly. Region 10039 decayed slightly losing a small amount of penumbral area. Although the region was mostly quiet, there is a significant chance of a major flare occurring anytime over the next couple of days. Region 10042 was quiet and stable. Region 10043 decayed slightly and the separation between the positive and negative polarity areas increased. Region 10044 developed further until it produced major flares during the evening. Some decay was observed after the flares and it remains to be seen whether or not the region will again become as active as it has been over the last day. Another major flare is a possibility. Region 10045 developed further and may be capable of minor M class flare production. Region 10047 decayed and had only a single tiny spot left at the end of the day. New region 10048 emerged quickly in the northeast quadrant. New region 10049 emerged in the southwest quadrant. New region 10050 emerged quickly in the southeast quadrant during the latter half of the day. A new spotted region rotated into view at the southeast limb but has not yet been numbered by SEC/NOAA. Flares and CMEs A total of 6 C and 7 M class events was recorded on July 26. Region 10044 produced an M4.9/1N flare at 00:10, a C5.8 flare at 03:19, an M1.1 flare at 06:42, an M1.3 flare at 08:29, a C2.7 flare at 13:15, a C3.0 flare at 13:42, a C4.2 flare at 15:32, a C3.8 flare at 16:13, a C9.5 flare at 18:29, an M1.0 flare at 19:03, a major M8.7 flare at 21:12 and an M4.6 flare at 22:38 UTC. A long duration major M5.3 long duration event peaking at 22:13 may have had its origin in region 10039. This event appears to have been 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 quiet to active on July 27 and quiet 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 10035 2002.07.15 S09W87 plage 10036 2002.07.15 17 S07W68 0500 CKO area too large 10037 2002.07.17 4 N15W58 0170 CAO 10038 2002.07.21 6 N16W14 0020 AXX 10039 2002.07.22 72 S16E22 0940 FKC beta-gamma-delta 10040 2002.07.22 S19W56 plage 10041 2002.07.22 N16W32 plage 10042 2002.07.22 3 S19W13 0030 CAO 10043 2002.07.23 20 N12E14 0160 DAO 10044 2002.07.23 42 S21E17 0430 EKI beta-gamma-delta 10045 2002.07.24 20 N05W10 0170 DAI 10046 2002.07.24 N15W04 plage 10047 2002.07.25 4 N07W62 0030 BXO 10048 2002.07.26 5 N18E52 0030 CAO area too small, too few spots area typo by 10049 2002.07.26 2 S06W30 0220 CSO SEC/NOAA, should be 0020. 10050 2002.07.26 4 S07E36 0010 BXO Total number of sunspots: 199 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) 2002.07 163.0 (1) 134.9 (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]