Solar Terrestrial Activity Report [Image] Last update September 28, 2002 at 05:50 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update 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 27. Solar wind speed ranged between 277 and 323 km/sec. Solar flare activity was low. Solar flux was 151.6, the planetary A index was 8 (S.T.A.R. calculated average value based on three hour Ap indices: (data not yet available)). Three hour interval K indices: 32122232 (planetary), 22123212 (Boulder). The background x-ray flux is at the class B6 level. Region 10117 rotated quietly out of view at the southwest limb. Region 10122 decayed further and only had negative polarity spots left at the end of the day. The region will rotate out of view early on Sept.29. Region 10125 reemerged quickly before noon and is currently developing moderately quickly. Region 10127 lost all remaining trailing spots and will rotate out of view late today. Region 10129 decayed and could soon become spotless. Region 10130 decayed slowly and quietly. Region 10131 reemerged with a few small spots but could soon become spotless again. Region 10132 decayed further and is currently simply structured. Unless new flux emerges the region is likely to remain quiet. Region 10133 decayed and was spotless by noon. Region 10134 developed with several new spots emerging. A central penumbra increased quickly in size and currently has a magnetic delta structure. Further M class flares are likely. Flares: Long duration C9.9 event peaking at 03:41, C4.8 at 08:24, M1.8 at 13:12, C3.2 at 16:55 and M1.4 at 19:42 UTC. New region 10135 emerged in the southeast quadrant near the central meridian. A long duration C5.3 event peaking at 01:49 UTC had its origin behind the southwest limb and caused a minor increase in the background proton flux. A filament eruption beginning at 07:36 UTC in the southwest quadrant was the origin of a partial halo CME covering the south pole and a large part of the west limb. Coronal mass ejections (CMEs) September 27: Lots of CMEs observed, none of which appeared to have geoeffective extensions. CMEs were observed off of the northeast limb following the larger eruptions in region 10134. Coronal holes A well placed coronal hole in the southern hemisphere was in a geoeffective position on September 26-27. Forecast The geomagnetic field is expected to be quiet to unsettled on September 28 and quiet to active on September 29-30 due to a coronal stream. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to good. 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 10117 2002.09.15 1 S08W89 0120 HSX 10120 2002.09.16 S19W88 plage 10121 2002.09.16 S12W81 plage 10122 2002.09.16 5 S18W71 0070 CAO area 0030 at midnight 10125 2002.09.18 5 S08W52 0030 CRO 12 spots observed at midnight, area 0050 10126 2002.09.19 S22W29 plage only 1 spot observed 10127 2002.09.20 7 S13W74 0190 CAO at midnight, classification HAX 10128 2002.09.20 N10W29 plage 10129 2002.09.22 11 N27W13 0010 BXO 10130 2002.09.22 9 N06W17 0150 DAO 10131 2002.09.22 2 S06W35 0000 BXO 10132 2002.09.22 12 N19W65 0190 DAI area 0150 at midnight, classification DAO 10133 2002.09.23 1 S27W29 0000 AXX spotless by noon 10134 2002.09.24 18 N11E38 0170 DAI beta-gamma-delta 10135 2002.09.27 4 S26E06 0040 DSO Total number of sunspots: 75 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) 2002.09 179.5 (1) 194.1 (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]