Solar Terrestrial Activity Report [Image] Last update September 6, 2001 at 06:20 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 1, 2001)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update September 1, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update September 1, 2001)] [Historical solar and geomagnetic data charts 1954-2001 (last update July 27, 2001)] Recent development The geomagnetic field was quiet to unsettled on September 5. Solar wind speed ranged between 388 and 523 km/sec. Solar flare activity was high. Solar flux was 218.3, the planetary A index was 10 (3-hour K indices: 3122 3332, Boulder K indices: 3221 2120). Region 9596 was quiet and stable. Region 9599 was quiet and stable. Region 9601 increased its areal coverage but lost some spots. Another major flare is possible from this region. Region 9603 was quiet and stable. Region 9604 rotated off the visible disk. Region 9605 decayed slowly and quietly. Region 9606 developed further and could produce at least minor M class flares. Region 9607 was mostly unchanged and may produce M class flares. New region 9608 rotated into view at the southeast limb and appears to be the main source of recent activity observed in the area. Another region is rotating into view further north on the southeast limb. A new region has developed in the southwest quadrant due south of region 9601. Flares and CMEs A total of 6 C and 3 M class events were observed on September 5. Region 9601 produced a C5.7 flare at 09:16 and an impulsive major M6.0/2B flare at 14:32 (no associated CME was observed) UTC. Region 9606 generated an M1.3/1N flare at 19:13 UTC. Region 9608 was the source of an M2.2 flare at 22:33 UTC. The background x-ray flux is at the class C3-C4 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 6-7. 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 9596 2001.08.25 1 N21W64 0160 HSX 9597 2001.08.26 N19W80 plage 9599 2001.08.27 1 S17W61 0020 HSX 9601 2001.08.27 40 N13W38 0830 EKI beta-gamma 9602 2001.09.01 S07W24 plage 9603 2001.09.02 1 S08E23 0020 HSX 9604 2001.09.03 4 S20W90 0100 DAO 9605 2001.09.03 4 S20E25 0030 CSO 9606 2001.09.03 19 S17E32 0210 DAO beta-gamma 9607 2001.09.04 9 S15E55 0230 EAO 9608 2001.09.05 6 S24E70 0320 EAO beta-gamma Total number of sunspots: 85 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.03 208.2 138.5 119.9 2000.04 184.2 125.5 120.8 cycle 23 sunspot max. 2000.07 202.3 170.1 119.7 2000.08 163.0 130.5 118.6 (-1.1) 2000.09 182.1 109.7 116.3 (-2.3) 2000.10 167.4 99.4 114.5 (-1.8) 2000.11 178.8 106.8 112.8 (-1.7) 2000.12 173.6 104.4 112.1 (-0.7) 2001.01 166.6 95.6 108.8 (-3.3) 2001.02 146.6 80.6 104.1 (-4.7) 2001.03 177.7 113.5 (102.8 predicted, -1.3) 2001.04 177.7 108.2 (102.0 predicted, -0.8) 2001.05 147.1 97.3 (100.5 predicted, -1.5) 2001.06 173.0 134.0 (97.7 predicted, -2.8) 2001.07 131.3 82.2 (95.9 predicted, -1.8) 2001.08 162.9 106.8 (96.4 predicted, +0.5) 2001.09 200.4 (1) 26.7 (2) (95.4 predicted, -1.0) 1) Running average based on the daily 20:00 UT solar flux value at 2800 MHz. 2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official international sunspot number 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 noted in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]