Solar Terrestrial Activity Report [Image] Last update August 22, 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 to active on August 21. Solar wind speed ranged between 326 and 369 km/sec. Solar flare activity was low. Solar flux was 151.4, the planetary A index was 12 (3-hour K indices: 2334 2323, Boulder K indices: 1324 2212). Region 9124 was quiet and stable and will rotate off the visible disk on August 23, the region appears to be spotless early on Aug.22. Region 9125 was fairly active producing many C flares. The region continued its decay and will rotate over the west limb early on August 23. Region 9128 reemerged with a single spot but is spotless again early on Aug.22. Region 9129 was quiet and stable. Region 9131 decayed slowly and was quiet. Region 9134 was quiet and stable, no spots are visible early on Aug.22. Region 9135 decayed and was quiet, the region is spotless early on Aug.22. Region 9136 decayed further and was quiet, no spots are visible early on Aug.22. Region 9137 decayed into spotless plage. Region 9138 was quiet and stable. Region 9139 developed slowly and could produce occasional C class flares. Flares and CMEs A total of 10 C class events were recorded on August 21. Region 9125 produced all optically assigned flares, a C2.0 flare at 00:16, a C1.9 flare at 03:12, a C4.1/1F flare at 05:38, a C2.8 flare at 07:58, a C2.3 flare at 13:02, a C1.7 flare at 13:40, a C1.0 flare at 19:22 and a C2.8 flare at 21:34 UTC. The background x-ray flux is at the class B6 level. Coronal holes A well defined coronal hole in the southern hemisphere was in a geoeffective position on August 20-21. Another coronal hole, in the northern hemisphere, was probably too far to the north to be geoeffective when it rotated across the central meridian on August 20-21. Forecast The geomagnetic field is expected to be quiet to unsettled on August 22. Coronal stream effects could start late on August 23 and cause unsettled to minor storm conditions. 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 3 S12W72 0020 CRO 9125 20000810 6 N26W76 0100 DAO 9128 20000812 1 N13W62 0000 AXX 9129 20000812 3 S05W47 0150 HAX 9131 20000813 2 N14W32 0060 CSO 9132 20000814 N20W39 plage 9134 20000814 4 N08W25 0010 BXO 9135 20000815 2 S13W73 0010 BXO 9136 20000817 3 N09W63 0010 BXO 9137 20000819 N24E20 plage 9138 20000819 1 S32E38 0040 HSX 9139 20000820 7 S10E09 0170 DAO Total number of sunspots: 32 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 2000.08 170.1 (1) 123.7 (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]