Solar Terrestrial Activity Report [Image] Last update August 10, 2000 at 04:05 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 unsettled on August 9. Solar wind speed ranged between 345 and 408 km/sec. Solar flare activity was low. Solar flux was 182, the planetary A index was 7 (3-hour K indices: 2212 2223, Boulder K indices: 2210 2213). Regions 9105 and 9107 were quiet and stable, both regions rotated off the visible disk early on August 10. Region 9110 was quiet and developed slowly. Region 9114 was mostly quiet and stable but could produce occasional C and minor M class flares. Region 9115 decayed slowly and was quiet. Regions 9116 was quiet and stable and could become spotless within a couple of days. Region 9117 decayed into spotless plage. Region 9119 decayed slowly and was quiet. Region 9120 decayed and could become spotless today or tomorrow. Region 9121 was quiet and stable. Region 9122 decayed slowly and was mostly quiet. Region 9123 was quiet and stable. The strong emissions at the southeast limb are caused by the return of old region 9087. Strong magnetic fields are observed at and near the limb, however, only a few spots are visible early on August 10. Minor M class flares are possible. An active region is rotating into view at the northeast limb. Flares and CMEs A total of 5 C class events were recorded on August 9. Region 9122 produced a C1.8 flare at 05:32. Spotless region 9111 generated a C2.3 flare at 16:22 UTC. A fairly extensive filament eruption was observed from 16:00 UTC, the eruption occurred in the northern hemisphere and spanned an area from near the solar equator northwards to region 9122, then westwards until in the vicinity of region 9114. A clear full halo CME was observed in LASCO C3 images following this eruption. A terrestrial impact will occur, probably on August 12, and cause the geomagnetic field to range from unsettled to major storming. The background x-ray flux is at the class B8 level. Coronal holes A small coronal hole in the southern hemisphere will rotate into a geoeffective position on August 12 and could cause unsettled to active intervals on August 15. Forecast The geomagnetic field is expected to be quiet to unsettled on August 10-11. Quiet to major storm is likely on August 12-13 as a result of the halo CME observed on August 9. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to 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 no. Location at region numbered sunspots midnight Area Classification Comment 9105 20000727 1 N16W88 0060 HSX 9107 20000729 1 S13W88 0030 HSX 9110 20000731 10 S18W59 0060 CAO 9111 20000801 N10W81 plage 9114 20000802 26 N11W16 0290 EKO beta-gamma 9115 20000803 5 N18E02 0130 CAO 9116 20000804 1 S12W02 0000 AXX 9117 20000805 S10W64 plage 9118 20000805 N18W64 plage 9119 20000805 6 S13W47 0030 CAO 9120 20000806 2 S22W17 0010 AXX 9121 20000806 2 S34W12 0100 DSO 9122 20000807 11 N21E21 0140 DAI 9123 20000808 1 N18E60 0060 HSX Total number of sunspots: 66 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 2000.08 161.3 (1) 46.7 (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]