Solar Terrestrial Activity Report [Image] Last update August 16, 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 active on August 15. Solar wind speed ranged between 411 and 588 km/sec. Solar flare activity was low. Solar flux was 193.9, the planetary A index was 12 (3-hour K indices: 4423 2322, Boulder K indices: 3413 3312). Region 9115 was quiet and stable and will rotate over the west limb today. Regions 9122 and 9123 were quiet and stable. Region 9124 developed slowly and may be capable of occasional C class flaring. Region 9125 was mostly unchanged and could produce a minor M class flare. Region 9127 developed quickly early in the day but seems to be decaying early on August 16. Occasional C class flares are possible. Region 9128 was quiet and stable, as was region 9129. Region 9130 decayed into spotless plage. Regions 9131 and 9132 were quiet and stable. Region 9133 decayed into spotless plage. Region 9134 was quiet and stable. New region 9135 emerged in the southeast quadrant and has been developing fairly quickly, C flares are possible. Flares and CMEs A total of 6 C class events were recorded on August 15. Region 9125 produced a C3.3 flare at 01:53, a C1.3 flare at 05:26, a C1.4 flare at 14:07, a C1.6 flare at 15:55 and a C1.4 flare at 20:29 UTC. A couple of filament eruptions were observed during the day. At 09:36 an eruption began between regions 9135 and 9129 in the southeast quadrant, there is a small possibility that the associated CME will influence the geomagnetic field on August 18. The background x-ray flux is at the class B9 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on August 16-17. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 9115 20000803 1 N20W79 0110 HSX 9116 20000804 S12W80 plage 9122 20000807 2 N23W58 0020 HSX 9123 20000808 2 N20W21 0020 HSX 9124 20000810 11 S12E07 0050 CSO 9125 20000810 34 N25E02 0320 DAI beta-gamma 9127 20000811 11 S35W31 0110 DSO 9128 20000812 4 N11E19 0030 DSO 9129 20000812 5 S07E33 0120 DSO 9130 20000813 S23W39 plage 9131 20000813 1 N13E45 0070 HSX 9132 20000814 5 N21E39 0030 CSO 9133 20000814 S09W10 plage 9134 20000814 1 N06E53 0010 HRX 9135 20000815 12 S15E14 0050 DSO 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 2000.08 171.9 (1) 84.4 (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]