Solar Terrestrial Activity Report [Image] Last update September 9, 2000 at 05:05 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update September 2, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update September 2, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update September 2, 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 September 8. Solar wind speed ranged between 344 and 521 km/sec. Another disturbance started around 06h UTC with the likely arrival of the (partial) halo CME observed on September 5. Solar flare activity was low. Solar flux was 163.4, the planetary A index was 21 (3-hour K indices: 3335 4433, Boulder K indices: 3334 3424). Region 9147 was quiet and stable, the region is rotating over the west limb. Region 9149 decayed slowly and was quiet, the region will rotate off the visible disk late today. Region 9151 was mostly unchanged and quiet. Region 9152 was quiet and stable, the region is spotless early on September 9. Region 9154 was generally unchanged and quiet. C and minor M class flares are possible. Region 9157 was quiet and stable, as were regions 9158 and 9159. Region 9159 appears to be spotless early on September 9. Flares and CMEs A total of 2 C class events were recorded on September 8. Region 9151 produced C1.0 flare at 04:06 UTC. The background x-ray flux is at the class B5 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions.. Forecast The geomagnetic field is expected to be quiet to unsettled on September 9-11. 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 9147 20000828 1 N08W80 0080 HSX 9149 20000828 5 N14W78 0250 EAO 9150 20000830 N12W53 plage 9151 20000831 9 N13W61 0110 DSO 9152 20000831 2 N19W29 0010 BXO 9153 20000831 S32W75 plage 9154 20000831 14 S17W49 0570 EKI beta-gamma 9155 20000903 S10W32 plage 9156 20000906 S28E23 plage 9157 20000906 1 N22E38 0010 HSX 9158 20000907 1 N30E56 0070 HSX 9159 20000907 2 S19E15 0010 AXX Total number of sunspots: 35 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) 2000.02 174.1 112.9 116.6 (+3.8) 2000.03 208.2 138.5 (120.1 predicted, +3.5) 2000.04 184.2 125.3 (122.5 predicted, +2.4) 2000.05 184.9 120.8 (123.4 predicted, +0.9) 2000.06 179.8 124.9 (124.9 predicted, +1.5) 2000.07 202.3 169.1 (127.0 predicted, +2.1) 2000.08 163.0 130.6 2000.09 166.5 (1) 43.0 (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]