Solar Terrestrial Activity Report [Image] Last update August 30, 2000 at 04:55 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 unsettled to minor storm on August 29. Solar wind speed ranged between 536 and 662 km/sec under the influence of a coronal stream. Solar flare activity was low. Solar flux was 163.3, the planetary A index was 31 (3-hour K indices: 5554 4443, Boulder K indices: 5564 4433). Region 9138 was quiet and stable. Region 9140 developed slowly and was quiet. C flares are possible. Region 9142 was quiet and stable. Region 9143 did not change significantly and remains capable of C and minor M class flare production. Region 9144 decayed slowly and was quiet. Region 9145 was mostly unchanged and quiet. Region 9146 reemerged with a couple of spots. Region 9147 could produce further C class flares. Region 9148 was quiet and stable. Region 9149 developed at a moderate pace and could produce M class flares. Flares and CMEs A total of 3 C class events were recorded on August 29. Region 9143 produced a C1.7 flare at 15:12 UTC. Region 9147 generated a C3.3 flare at 15:19 UTC. A long duration C4.2 event started at 22:35 UTC and peaked at 00:08 UTC on August 30. This was a large filament eruption occurring in the vicinity of region 9148 and 9143 in the southeast quadrant. A CME was observed off the southeast limb and will have to be studied further to determine if part of the CME could be headed towards Earth. A large CME was observed off the southwest limb following a filament eruption which began at 07:25 UTC. A wide and large CME was seen in LASCO images at about 18h UTC from a source 5-6 days behind the northwest limb. The background x-ray flux is at the class B8 level. Coronal holes A coronal hole in the northern hemisphere was in a geoeffective position on August 27-28. Forecast The geomagnetic field is expected to be quiet to active on August 30-31. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very 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 9137 20000819 N24W84 plage 9138 20000819 1 S27W63 0020 AXX 9140 20000822 16 N10W27 0180 DAO 9141 20000823 N16W86 plage 9142 20000824 1 N15E09 0020 HSX 9143 20000824 21 S19E08 0290 EAI beta-gamma 9144 20000825 13 N26W38 0170 EAO 9145 20000827 5 S10E34 0050 DAO 9146 20000827 2 S28E26 0010 BXO 9147 20000828 3 N04E53 0090 HAX 9148 20000828 1 S19E32 0020 HSX 9149 20000828 12 N10E57 0280 EAI beta-gamma Total number of sunspots: 75 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 (115.7 predicted, +2.9) 2000.03 208.2 138.5 (118.2 predicted, +2.5) 2000.04 184.2 125.3 (120.4 predicted, +2.2) 2000.05 184.9 120.8 (121.2 predicted, +0.8) 2000.06 179.8 124.9 (122.8 predicted, +1.6) 2000.07 202.3 169.1 2000.08 163.0 (1) 153.7 (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]