Solar Terrestrial Activity Report [Image] Last update October 15, 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 October 13, 2002)] Recent activity The geomagnetic field was quiet to major storm on October 14. Solar wind speed ranged between 297 and 443 km/sec. A coronal stream dominated the solar wind after noon. As is fairly often the case with coronal streams, the solar wind several hours ahead of it was compressed causing an increase both in solar wind density and the total field of the interplanetary magnetic field. The source of the coronal stream is a large extension of the northern polar coronal hole, this extension was in a geoeffective position on October 11. Solar flare activity was low. Solar flux was 181.2, the planetary A index was 26 (S.T.A.R. Ap - based on the mean of three hour ap indices: 26.4). Three hour interval K indices: 34446432 (planetary), 23444422 (Boulder). The background x-ray flux is at the class B7 level. At midnight there were 10 spotted regions on the visible disk. A total of 7 C class events were recorded during the day. This included a very long duration C4.3 event peaking just after 18h UTC. There was a data gap in LASCO data from 14:20 to 20:20 UTC and this prevented an observation of the event itself. Based on LASCO data available after 20h UTC there is no doubt there was a very large full halo CME associated with the VLDE. The observed ejected material was denser off the east limb. In the absence of obvious front side activity, this indicates an origin behind the east limb. Region 10139 decayed slowly and rotated out of view at the northwest limb early on Oct.15. Region 10140 was quiet. The region gained a small trailing spot during the day. Region 10144 was quiet. Several small trailing spots emerged. Region 10145 was quiet. A few trailing spots became visible. Region 10148 was quiet and stable. Region 10149 was mostly unchanged and quiet. The leading penumbra in the southwest increased its areal coverage. This region appears to consist of 3 separate regions. In magnetograms there is a clear separation between the negative and positive polarity areas of the northern and southern spots. The southern spots are aligned on on east-west axis while the northern polarity areas are more along a northeast to southwest axis. A new bipolar region emerged late on October 13 north of the largest northern penumbra. This region developed slowly during the day and had 4 small spots by late evening. A minor M class flare is possible. Region 10154 lost some of its penumbral area. Several small spots without penumbra emerged during the day. Region 10157 decayed and was spotless by midnight. Region 10158 was quiet and stable. Region 10159 was mostly unchanged. Flare: C4.7 at 09:45 UTC. New region 10160 emerged near the southeast limb on October 13 and developed slowly early on October 14. Coronal mass ejections (CMEs) October 13: A C4.7 flare in spotless region 10150 was associated with a small CME observed over the southwest limb. An M2.2 long duration event beginning late in the day near region 10159 was associated with a large halo CME. Although most of the ejected material was observed off of the east limb, a faint front all around the disk was noticed in LASCO C3 images. A weak shock is possible on October 16 or 17. October 14: A huge full halo CME was observed in LASCO C3 images in association with a very long duration C4.3 event peaking just after 18h UTC. With an origin behind the east limb, the CME is unlikely to have been geoeffective. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be mostly quiet to active on October 15-16 due to a coronal stream. A weak solar wind shock is possible on October 16 or 17 but is not likely to increase geomagnetic activity beyond active levels. 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 10139 2002.10.02 7 N08W85 0330 DKO 10140 2002.10.04 4 S08W52 0170 CSO 2 spots observed at midnight 10142 2002.10.05 N05W56 plage 10144 2002.10.07 3 N11W52 0100 CSO 10145 2002.10.08 3 N12W05 0090 CSO 10146 2002.10.09 S09W44 plage 10147 2002.10.09 S03W27 plage 10148 2002.10.09 1 S20E04 0030 HSX 10149 2002.10.09 31 N14E06 0440 EHI region consists of 3 separate regions 10150 2002.10.09 S09W58 plage 10151 2002.10.09 S14W15 plage 10152 2002.10.10 N20W68 plage 10153 2002.10.10 S05W05 plage 10154 2002.10.10 9 S12E21 0040 EAO classification DRO at midnight 10156 2002.10.11 N09W30 plage 10157 2002.10.12 2 N15E20 0010 CRO now spotless 10158 2002.10.12 1 S08E47 0110 HSX 10159 2002.10.13 1 S11E57 0140 HAX 10160 2002.10.14 3 S20E54 0030 CRO Total number of sunspots: 65 Monthly solar data Average Month solar International sunspot Smoothed sunspot flux at number number Earth 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) 2002.10 163.2 (1) 67.6 (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]