Solar Terrestrial Activity Report [Image] Last update August 29, 2001 at 03:40 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 1, 2001)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update August 1, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update August 1, 2001)] [Historical solar and geomagnetic data charts 1954-2001 (last update July 27, 2001)] Recent development The geomagnetic field was quiet to active on August 28. Solar wind speed ranged between 458 and 592 km/sec. Solar flare activity was moderate. Solar flux was 199.2, the planetary A index was 15 (3-hour K indices: 4333 3432, Boulder K indices: 4323 2332). Region 9585 decayed quietly and has rotated over the west limb. Region 9587 rotated off the visible disk. Region 9590 was quiet and stable. Region 9591 decayed slowly and was less active than its has been recently. There is still a strong magnetic delta within the main penumbra and the region could produce a major flare. Region 9595 reemerged with a couple of spots but was spotless again by late evening. Region 9596 was quiet and stable. Region 9597 developed early in the day, then decayed and could become spotless again today. Region 9598 rotated quietly off the visible disk. Region 9599 developed slowly and was quiet. Regions 9600 and 9601 are capable of M class flaring and still appear to be one region in magnetograms. Flares and CMEs A total of 16 C and 3 M class events were observed on August 28. Region 9591 produced an M1.0/1N flare at 00:12 and a C6.3 flare at 10:10 UTC. Region 9587 generated a C4.0 flare at 03:33, a C5.5 flare at 12:29 and a C9.4 flare at 13:41 UTC. Region 9600 was the source of a C6.1 flare at 02:03, a C4.2 flare at 06:58, a C5.1 flare at 11:49, a C5.7 flare at 15:39, a C6.1 flare at 19:47 and a C6.5 flare at 20:08 UTC. Region 9601 produced an M1.2 flare at 08:40, an M1.1/1F flare at 16:11 (with an associated strong type II sweep and a weak type II radio sweep. A CME was observed off the east limb after this event.), a C2.4 flare at 18:35 and a C2.6 flare at 21:1 UTC. 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 unsettled on August 29-30. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 9585 2001.08.16 2 N12W85 0030 CSO 9587 2001.08.17 6 S10W90 0100 DAO 9590 2001.08.20 3 S26W31 0150 HSX 9591 2001.08.21 41 S19W06 0620 FKI beta-gamma-delta 9593 2001.08.23 N00W64 plage 9594 2001.08.24 N37W49 plage 9595 2001.08.24 2 N15W31 0010 AXX 9596 2001.08.25 1 N22E40 0160 HAX 9597 2001.08.26 9 N17E22 0040 DAO 9598 2001.08.27 1 S17W88 0030 HAX 9599 2001.08.27 3 S17E51 0080 DAO 9600 2001.08.27 4 N16E68 0170 DAO 9601 2001.08.27 7 N12E73 0150 DAO beta-gamma Total number of sunspots: 79 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.03 208.2 138.5 119.9 2000.04 184.2 125.5 120.8 cycle 23 sunspot max. 2000.07 202.3 170.1 119.7 2000.08 163.0 130.5 118.6 (-1.1) 2000.09 182.1 109.7 116.3 (-2.3) 2000.10 167.4 99.4 114.5 (-1.8) 2000.11 178.8 106.8 112.8 (-1.7) 2000.12 173.6 104.4 112.1 (-0.7) 2001.01 166.6 95.6 108.8 (-3.3) 2001.02 146.6 80.6 (104.1 predicted, -4.7) 2001.03 177.7 113.5 (101.4 predicted, -2.7) 2001.04 177.7 108.2 (100.2 predicted, -1.2) 2001.05 147.1 97.3 (99.5 predicted, -0.7) 2001.06 173.0 134.0 (96.8 predicted, -2.7) 2001.07 131.3 82.2 (94.9 predicted, -1.9) 2001.08 159.4 (1) 146.0 (2) (95.5 predicted, +0.6) 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 25-40% 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] [StudyWeb]