Solar Terrestrial Activity Report [Image] Last update August 19, 2000 at 04:35 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 18. Solar wind speed ranged between 299 and 350 km/sec. Solar flare activity was low. Solar flux was 169.5, the planetary A index was 6 (3-hour K indices: 2222 2222, Boulder K indices: 1210 0001). Region 9123 was quiet and stable. Region 9124 decayed slowly and was quiet. Region 9125 was mostly unchanged and quiet. An increase in activity was observed during the last six hours of the day and the region should continue to produce C flares. Region 9127 could produce further C flares before rotating off the visible disk on August 20. Region 9128 was quiet and stable. Region 9129 developed slowly and could produce C class flares. Region 9131 did not change significantly and could produce occasional C class flares. Region 9132 decayed slowly and was quiet, the region is spotless early on August 19. Region 9133 was quiet and stable. Region 9134 was quiet and stable. Region 9135 decayed slowly and was quiet. Region 9136 developed slowly and was quiet. Flares and CMEs A total of 3 C class events were recorded on August 18. Region 9127 produced a long duration C5.5/1F event peaking at 04:45 UTC. Region 9125 generated a C1.1 flare at 18:10 and a C1.3 flare at 23:55 UTC. The background x-ray flux is at the class B6 level. Coronal holes A well defined coronal hole in the southern hemisphere will rotate into a geoeffective position on August 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 21. Forecast The geomagnetic field is expected to be quiet to unsettled on August 19-21. 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 9123 20000808 4 N21W57 0010 BXO 9124 20000810 13 S13W36 0020 BXO 9125 20000810 34 N26W36 0180 EAI beta-gamma 9127 20000811 4 S37W67 0140 DAO 9128 20000812 10 N10W19 0030 DRO 9129 20000812 7 S05W06 0190 CSO 9130 20000813 S23W78 plage 9131 20000813 5 N14E07 0100 CSO 9132 20000814 1 N21E01 0000 AXX 9133 20000814 3 S10W50 0000 BXO 9134 20000814 4 N08E15 0010 BXO 9135 20000815 17 S12W26 0110 DAO 9136 20000817 9 N07W20 0060 DAO Total number of sunspots: 111 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 2000.08 172.8 (1) 107.9 (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]