Solar Terrestrial Activity Report [Image] Last update October 27, 2002 at 04:30 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 unsettled to minor storm on October 26. Solar wind speed ranged between 502 and 657 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 158.0, the planetary A index was 27 (STAR Ap - based on the mean of three hour ap indices: 28.3). Three hour interval K indices: 34455443 (planetary), 35444442 (Boulder). The background x-ray flux is at the class B5 level. At midnight there were 8 spotted regions on the visible disk, 2 of which have not yet been numbered. A total of 4 C class events were recorded during the day. Region 10162 decayed in the southern and central section of the trailing spots. Some development was observed in the northwestern part of the trailing spots. An M class flare is possible. Flares: C2.9 at 03:13 and C2.3 at 18:28 UTC. Region 10165 decayed slowly and quietly. Region 10167 was quiet and stable. Region 10169 was quiet and stable. Region 10170 added some small spots and was quiet. Region 10171 was unchanged and quiet. Spotted regions not yet numbered: [S09] Region rotated into view at the southeast limb early on October 26. Location at midnight: S17E66. [S10] New region emerged in the northeast quadrant. The region appeared to be decaying late in the day. Position at midnight: N08E34. Coronal mass ejections (CMEs) October 24: A full halo CME was observed at 08:50 UTC in LASCO images. With no obvious front side source it is likely that this CME had a source about 5-6 days behind the southwest limb. Another full halo CME was first visible in LASCO C2 images at 21:26 UTC. Again no obvious front side activity could be associated with this CME. Its likely origin is several days behind the west limb. October 25: A full halo CME was observed in LASCO C3 images beginning at 10:42 UTC. The source of this CME was likely the same as that of the two halo CMEs observed on October 24. It should be noted that there was a large eruption in the southeast quadrant shortly before the observation of this CME. Material from this eruption was observed along the southeastern front of the full halo CME and there is a possibility that some if this material could reach Earth on October 27 or 28. Another full halo CME was observed beginning at 15:42 UTC in LASCO C3 images. The source was likely from the same region that had produced 3 other full halo CMEs on Oct.24-25. A CME was observed above the north pole and the northwest limb starting at 18:42 UTC and was associated with the M1 event in region 10162. This CME does not appear to have any geoeffective components. October 26: Another full halo CME was observed after 08h UTC. The source of this CME is likely the same southern hemisphere region being the source of the 4 full halo CMEs observed on October 24-25. Interestingly, SOHO MDI far side images reveal a large region in the same position as would be expected from the material distribution observed during all the halo CMEs. Further large CMEs could be observed before the region rotates into view on November 1-2. Coronal holes A small coronal hole has formed in the southeast quadrant near the equator and could rotate into a geoeffective position on October 27. Forecast The geomagnetic field is expected to be quiet to active on October 27-28. 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) Data for all numbered solar regions according to the Solar Region Summary provided by SEC/NOAA. Comments are my own, as is the STAR spot count (spots observed at or just prior to midnight) and data for regions not numbered by SEC or where SEC has observed no spots. Solar Date SEC STAR Location region numbered spot spot at AreaClassification Comment countcount midnight beta-gamma 10162 2002.10.17 64 41 N26W27 0920 FKC classification should be FKI, area was near 0600 at midnight 10164 2002.10.20 N11W26 plage 10165 2002.10.20 8 6 N21W09 0150 DAO classification should be HAX 10166 2002.10.23 S06W31 plage 10167 2002.10.23 2 1 N18E36 0040 CSO 10169 2002.10.24 2 2 S19E47 0100 DSO 10170 2002.10.25 6 4 S12E53 0030 CSO 10171 2002.10.25 1 1 N10E64 0060 HSX S09 visible on 1 S17E66 0030 HSX 2002.10.26 S10 emerged on 2 N08E34 0020 DRO 2002.10.26 Total spot count: 83 58 SSN: 143 138 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) 2002.04 189.8 120.7 (109.7 predicted, -3.7) 2002.05 178.4 120.8 (105.9 predicted, -3.8) 2002.06 148.7 88.3 (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) 2002.10 167.8 (1) 129.8 (2) (84.6 predicted, -4.1) 1) Running average based on the daily 20:00 UT observed 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]