Solar Terrestrial Activity Report [Image] Last update August 20, 2000 at 04:50 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 19. Solar wind speed ranged between 308 and 373 km/sec. Solar flare activity was low. Solar flux was 157.1, the planetary A index was 6 (3-hour K indices: 2112 2322, Boulder K indices: 1110 1211). Region 9123 decayed into spotless plage. Region 9124 developed slowly and was quiet. Region 9125 decayed slowly but could produce further C class flares. Region 9127 was quiet and stable and is rotating over the west limb. Region 9128 was quiet and stable. Region 9129 decayed slowly and could produce occasional C class flares. Region 9131 was quiet and stable. Region 9132 decayed into spotless plage. Region 9133 was quiet and stable, as was region 9134. Region 9135 decayed slowly and was quiet. Region 9136 developed slowly and was quiet. New region 9137 emerged in the northeast quadrant and appears to be spotless already. New region 9138 rotated into view at the southeast limb. Flares and CMEs A total of 3 C class events were recorded on August 19. Region 9125 produced a C5.0 flare at 04:39, a C2.2 flare at 05:53 and a C4.1/1F flare at 19:25 UTC. The background x-ray flux is at the class B4 level. Coronal holes A well defined coronal hole in the southern hemisphere will rotate into a geoeffective position on August 20-21. Another coronal hole, in the northern hemisphere, is probably too far to the north to be geoeffective when in rotates across the central meridian on August 20-21. Forecast The geomagnetic field is expected to be quiet to unsettled on August 20-22. 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 9123 20000808 N21W70 plage 9124 20000810 11 S12W49 0050 CRO 9125 20000810 28 N27W49 0130 EAI beta-gamma 9127 20000811 1 S38W77 0080 HSX 9128 20000812 10 N10W34 0030 CAO 9129 20000812 5 S06W19 0150 CSO 9131 20000813 4 N15W07 0110 CSO 9132 20000814 N20W13 plage 9133 20000814 3 S10W64 0000 BXO 9134 20000814 4 N09E02 0010 AXX 9135 20000815 9 S12W41 0050 CSO 9136 20000817 11 N06W33 0070 DAO 9137 20000818 2 N23E45 0010 BXO 9138 20000818 1 S32E64 0030 HRX Total number of sunspots: 89 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 2000.08 172.0 (1) 114.6 (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]