Solar Terrestrial Activity Report [Image] Last update October 6, 2002 at 03:35 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 unsettled to minor storm on October 5. Solar wind speed ranged between 362 and 471 km/sec. Solar flare activity was high. Solar flux was 155.1, the planetary A index was 29 (S.T.A.R. calculated average value based on three hour Ap indices: 29.1). Three hour interval K indices: 44355533 (planetary), 44344423 (Boulder). The background x-ray flux is at the class B8 level. Region 10134 decayed slowly losing only a small amount of penumbral area in the leading spot section. continued to decay quickly. The region will rotate out of view at the northwest limb on Oct.7. Region 10137 decayed. While the leading spot section was generally unchanged, quick decay was observed in the trailing spots. The magnetic delta disappeared early in the day. There is currently only a minor chance of a low level M class flare occurring. Flares: C2.8 at 02:38, C3.4 at 07:31 and C1.3 at 11:32 UTC. Region 10138 was spotless all day in all available images. [See comment in Active solar regions table below.] Region 10139 developed slowly adding penumbral area in all parts of the region. The magnetic delta observed on October 4 disappeared as the trailing spots separated from the central spots. Another major flare is possible. Flares: C2.0 at 07:53 and a major M5.9/1F event peaking at 21:00 UTC. A weak type II sweep was associated with the major flare. Region 10140 was quiet and stable. New region 10141 emerged in the southeast quadrant. New region 10142 rotated into view at the northeast limb. 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 (no LASCO images covering the hours after the eruption are currently available), 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 quiet to active on October 6. A coronal stream is likely to arrive on October 7 and could cause unsettled to active conditions that day and the next couple of days. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 8 N13W70 0180 DAO area approx. 0070 at midnight beta-gamma 10137 2002.09.29 22 S19W33 0230 EAI area approx. 0180 at midnight actually spotless! Please observe that the position was N10W51 one day earlier. The reported 10138 2002.10.01 3 N15W68 0020 HSX spots are actually the trailing spots in region 10134. Truly a major mistake by the forecaster at SEC. 10139 2002.10.02 44 N12E32 0680 DKC beta-gamma area actually closer to 0130. Typo? New, small 10140 2002.10.04 5 S07E62 0230 CAO leading spots emerged, these spots can be argued to belong to a new region. 10141 2002.10.05 2 S07E20 0020 BXO 10142 2002.10.05 1 N07E64 0010 AXX Total number of sunspots: 85 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) 2002.10 146.8 (1) 17.5 (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]