Solar Terrestrial Activity Report [Image] Last update September 22, 2002 at 07:15 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 3, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update September 3, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update September 3, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update August 16, 2002)] Recent activity The geomagnetic field was quiet to unsettled on September 21. Solar wind speed ranged between 380 and 451 km/sec. Solar flare activity was low. Solar flux was 158.6, the planetary A index was 9. K indices calculated for three hour intervals: 22233222 (planetary), 22222312 (Boulder). The background x-ray flux is at the class B6 level. Region 10114 was not visible at any time of the day. Yet SEC/NOAA claimed to have observed a one spot group, see active region table below for further comments. Region 10115 was quiet and stable. Region 10116 decayed and had only a single small spot left by the end of the day. The region appears to have become spotless early on Sept.22. Region 10117 was quiet and stable. Region 10119 developed slowly A new magnetic delta structure emerged within the trailing spots. M class flares are possible. Flare: C2.6 at 17:03 UTC. Region 10120 was spotless all day in all available images. Mt.Wilson did not observe anything either, yet SEC/NOAA claimed there were three small spots. Region 10121 was mostly quiet and stable. Flare: C3.0 at 03:20, this flare was associated with a weak type II sweep. Region 10122 was quiet and stable. Region 10123 decayed losing most of the smaller spots. Both the region northeast of region 10123 (and mistakenly included in this region by SEC/NOAA) and the original region 10123 decayed. Flare: C2.6 long duration event peaking at 21:00 UTC. Region 10125 was spotless all day in all available images. A filament near the region is displaying quite a bit of activity and could soon erupt. Region 10126 decayed slowly. No further M class flaring appears likely at this time. Region 10127 developed slowly and may be capable of producing a minor M class flare. Region 10128 decayed and was spotless by late afternoon. Four new regions emerged but were not noticed by SEC/NOAA! One is a new region with a single small spot near N25E65. Another slowly developing region was noted near S04E50. A small region emerged near the northeast limb just north of N05. A quickly developing region is currently near N20E10, this region could soon become capable of producing C and minor M class flares. Coronal mass ejections (CMEs) No CMEs of interest was observed on September 21. Coronal holes A poorly defined coronal hole in the northern hemisphere could rotate into a geoeffective position on September 23. Forecast The geomagnetic field is expected to be quiet to unsettled on September 22-24. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair. 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 Location region numbered no. at Area Classification Comment sunspots midnight position was S11W84 one day earlier and region would normally 10114 2002.09.14 1 S14W87 0020 HAX rotate to S11W97. No spots observed, not even very early in the day! 10115 2002.09.14 3 S04W55 0160 CAO 10116 2002.09.15 3 N15W73 0040 CSO area was 0020 at best. Now spotless. 10117 2002.09.15 2 S09W07 0170 HSX 10118 2002.09.16 N13W53 plage 10119 2002.09.16 31 S14W36 0670 DKC beta-gamma-delta spotless all day in all available images! Another 10120 2002.09.16 3 S19W10 0010 BXO day with poor data quality in SECs spot summary report 10121 2002.09.16 1 S13W02 0050 HAX 10122 2002.09.16 1 S18E09 0060 HSX actually two separate 10123 2002.09.17 14 S15W21 0060 DAO regions. Spot count too high. 10124 2002.09.18 N03W89 plage 10125 2002.09.18 3 S09E27 0020 CAO spotless all day 10126 2002.09.19 5 S23E52 0100 DAO area estimated at 0060 10127 2002.09.20 19 S14E05 0130 DAO beta-gamma 10128 2002.09.20 1 N10E49 0010 AXX now spotless Total number of sunspots: 87 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.04 184.2 125.5 120.8 cycle 23 sunspot max. 2000.07 202.3 170.1 119.8 2001.08 162.9 106.4 113.6 (+1.8) 2001.09 233.2 150.7 114.1 (+0.5) 2001.10 207.6 125.5 114.0 (-0.1) 2001.11 210.6 106.5 115.5 (+1.5) 2001.12 235.1 132.2 114.6 (-0.9) 2002.01 226.6 114.1 113.5 (-1.1) 2002.02 205.0 107.4 114.7 (+1.2) 2002.03 179.5 98.4 (113.2 predicted, -1.5) 2002.04 189.8 120.4 (108.7 predicted, -4.5) 2002.05 178.4 120.8 (104.2 predicted, -4.5) 2002.06 148.7 88.5 (99.7 predicted, -4.5) 2002.07 173.5 99.9 (94.9 predicted, -4.8) 2002.08 183.6 116.4 (90.8 predicted, -4.1) 2002.09 186.7 (1) 152.8 (2) (87.1 predicted, -3.7) 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 25-45% 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]