Solar Terrestrial Activity Report [Image] Last update October 7, 2002 at 03:05 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update October 2, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update October, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update October 2, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update August 16, 2002)] Recent activity The geomagnetic field was quiet to minor storm on October 6. The single minor storm interval was caused by a burst of activity during the 07-08h UTC interval. Solar wind speed ranged between 349 and 418 km/sec. Solar flare activity was moderate. Solar flux was 161.7, the planetary A index was 19 (S.T.A.R. calculated average value based on three hour Ap indices: 17.8). Three hour interval K indices: 24523333 (planetary), 24522323 (Boulder). The background x-ray flux is at the class B5 level. Region 10134 decayed slowly and had rotated out of view late in the day. Region 10137 decayed slowly and quietly. Region 10139 developed slowly with the main penumbral area expanding. The trailing negative polarity penumbral area, which had separated from the central positive polarity area yesterday, again appears to become part of the main penumbra, thereby creating a magnetic delta structure. The possibility of another major flare is slowly increasing. Flares: M2.4 at 04:51 and M1.0 at 11:55 UTC. Region 10140 was quiet and stable. [Please see comments below about the leading spots] Region 10141 developed slowly and quietly. Region 10142 was quiet and stable. There are currently two unnumbered spotted regions on the visible disk. One of them is located due west of region 10140 and had 5 spots late on Oct.6, the region emerged on October 5. SEC has included these spots in region 10140. Another new region emerged during the latter half of Oct.6 and was located near S18E20 at midnight. Coronal mass ejections (CMEs) October 4: Several CMEs were observed during the day, none of them large or obviously geoeffective. October 5: Outside of a possible CME associated with the major flare in region 10139, there were no CMEs of interest. Coronal holes A moderately large coronal hole in the southern hemisphere was in a geoeffective position on October 4-6. Forecast The geomagnetic field is expected to be unsettled to active on October 7-8 due to a coronal stream. Isolated minor storm interval are possible. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor to 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) SEC Solar Date number Location region numbered of at Area Classification Comment spots midnight 10134 2002.09.24 3 N12W85 0090 DSO 10137 2002.09.29 17 S19W48 0210 EAI classification DAO at midnight 10138 2002.10.01 N10W77 plage beta-gamma 10139 2002.10.02 32 N11E19 0570 EKI classification DKC at midnight The leading 5 spots make up a separate CSO region (located at 10140 2002.10.04 6 S07E50 0160 CAO S08E47 at midnight). The large trailing spot is a HSX region (location S08E55 at midnight) 10141 2002.10.05 7 S07E05 0040 DSO 10142 2002.10.05 1 N06E50 0020 HSX ? emerged (5) S08E47 0020 CSO 2002.10.05 ? emerged (1) S18E20 0010 AXX 2002.10.06 Total number of sunspots: 66 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 2001.09 233.2 150.7 114.1 (+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 98.4 113.4 (-1.3) 2002.04 189.8 120.4 (109.7 predicted, -3.7) 2002.05 178.4 120.8 (105.9 predicted, -3.8) 2002.06 148.7 88.5 (101.4 predicted, -4.5) 2002.07 173.5 99.9 (96.5 predicted, -4.9) 2002.08 183.6 116.4 (92.5 predicted, -4.0) 2002.09 175.8 109.3 (88.7 predicted, -3.8) 2002.10 149.3 (1) 21.4 (2) (84.6 predicted, -4.1) 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]