Solar Terrestrial Activity Report [Image] Last update August 23, 2000 at 04:40 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 4, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update August 4, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update August 4, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update August 10, 2000)] Recent development The geomagnetic field was quiet on August 22. Solar wind speed ranged between 295 and 344 km/sec. Solar flare activity was low. Solar flux was 144.2, the planetary A index was 5 (3-hour K indices: 2211 1222, Boulder K indices: 2221 1001). Region 9124 decayed into spotless plage. Region 9125 decayed further and was quiet, the region is rotating off the visible disk. Region 9128 once again decayed into spotless plage. Region 9129 was mostly quiet and stable. Region 9131 developed a few more spots and could produce additional C class flares. Region 9134 decayed into spotless plage, as did regions 9135 and 9136. Region 9138 was quiet and stable. Region 9139 developed slowly and could produce occasional C class flares. New region 9140 rotated into view at the northeast limb. Further active regions at and just behind the east limb will rotate into view over the next 2-3 days.. Flares and CMEs A total of 8 C class events were recorded on August 22. Region 9131 produced a C1.1 flare at 05:16 and a C2.7 flare at 09:44 UTC. Region 9129 generated a C1.3 flare at 06:02 UTC. Region 9139 was the source of a C1.5 flare at 17:35 UTC. The background x-ray flux is at the class B4 level. Coronal holes A well defined coronal hole in the southern hemisphere was in a geoeffective position on August 20-21. A coronal hole in the northern hemisphere will rotate into a geoeffective position on August 26. Forecast The geomagnetic field is expected to be initially quiet on August 23. Coronal stream effects could start late on August 23 and cause unsettled to active conditions, perhaps with an isolated minor storm interval. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair. 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 no. Location at region numbered sunspots midnight Area Classification Comment 9124 20000810 S12W85 plage 9125 20000810 4 N25W87 0050 CRO 9128 20000812 N13W75 plage 9129 20000812 3 S05W61 0130 HAX 9131 20000813 5 N14W45 0060 CAO 9132 20000814 N20W52 plage 9134 20000814 N08W38 plage 9135 20000815 S13W86 plage 9136 20000817 N09W76 plage 9137 20000819 N24E07 plage 9138 20000819 1 S32E26 0050 HSX 9139 20000820 10 S10W04 0190 DAO 9140 20000822 1 N08E69 0000 AXX Total number of sunspots: 24 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.07 165.6 113.5 94.3 (+1.2) 1999.08 170.7 93.7 97.5 (+3.2) 1999.09 135.7 71.5 102.3 (+4.8) 1999.10 164.8 116.7 107.8 (+5.5) 1999.11 191.5 133.2 110.9 (+3.1) 1999.12 169.8 84.6 111.0 (+0.1) 2000.01 158.1 90.1 112.8 (+1.8) 2000.02 174.1 112.9 (117.0 predicted, +4.2) 2000.03 208.2 138.5 (120.7 predicted, +3.7) 2000.04 184.2 125.3 (122.9 predicted, +2.2) 2000.05 184.9 120.8 (123.7 predicted, +0.8) 2000.06 179.8 124.9 (125.3 predicted, +1.6) 2000.07 202.3 169.1 2000.08 168.9 (1) 126.4 (2) 1) Running average based on the daily 20:00 UTC solar flux value at 2800 MHz. 2) Unofficial, accumulated value. The official value 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 in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]