Solar Terrestrial Activity Report [Image] Last update October 17, 2002 at 02:30 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 quiet to minor storm on October 16. Solar wind speed ranged between 449 and 672 km/sec under the influence of a high speed coronal stream. At 16:10 UTC ACE solar wind data indicate the arrival of another disturbance. Shortly afterwards the interplanetary magnetic field swung moderately southwards and this caused an increase in geomagnetic activity to active to minor storm levels over the next few hours. This additional disturbance may have been related to the arrival of the CME observed after the long duration M2.2 event near region 10159 on October 13/14. Solar flare activity was low. Solar flux was 182.5, the planetary A index was 14 (S.T.A.R. Ap - based on the mean of three hour ap indices: 14.1). Three hour interval K indices: 32123453 (planetary), 21122343 (Boulder). The background x-ray flux is at the class B7 level. At midnight there were 16 spotted regions on the visible disk, 5 of which has not yet been numbered. A total of 7 C class events were recorded during the day. Spotless region 10150 was the origin of a C2.9 flare at 04:24 UTC. Region 10140 decayed slowly and quietly and will rotate out of view at the southwest limb today. Region 10144 decayed and could soon become spotless. The region will rotate over the northwest limn today. Region 10145 was quiet and stable. Region 10148 was quiet and stable. Region 10149 decayed slowly losing several trailing spots. The large leading penumbrae were mostly unchanged. This region appears to encompass 3 bipolar regions, none of which has intermixed polarities. Flare: C1.2 at 14:49 UTC. Region 10154 added several small trailing spots and remained quiet. Region 10157 reemerged late in the day with several small spots. Region 10158 was quiet and stable. Region 10159 was mostly unchanged and quiet. Region 10160 developed quickly early in the day and had mixed polarities then. Later on the negative and positive polarity areas drifted slowly apart and the region is currently developing slowly. C class flares are possible. Flares: C7.1 at 03:14 and C1.8 at 11:49 UTC. Region 10161 decayed and could soon become spotless. Spotted regions which have not yet been numbered: 1. [S01] A new region emerged on October 14 just north of region 10149. The region developed slowly on October 15, then began to decay on October 16. Location at midnight: N19W20. 2. [S02] A new region emerged on October 15 in the southeast quadrant due west of region 10160. The region decayed slightly on October 16. Location at midnight: S21E16. 3. [S03] A new region emerged in the southeast quadrant northeast of region 10158 on October 15. The region has been developing slowly and currently has mixed polarities. Location at midnight: S04E25. 4. [S04] A new region emerged in the southeast quadrant just northeast of region 10159 on October 15. The region was mostly unchanged on October 16. Location at midnight: S08E33. 5. [S05] A new region is rotating into view at the northeast limb. Currently only a large penumbra can be seen. This region is probably capable of producing M class flares and was the likely source of the very long duration C4.3 event recorded on October 14. Flare: A long duration C6.5 event peaking at 16:27 UTC. Coronal mass ejections (CMEs) October 14: A large 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 a couple of days behind the northeast limb, the CME is unlikely to have been geoeffective. October 15: A large filament/prominence in the southern hemisphere lifted off. Activity began as early as 21:36 UTC on October 14 with the most noticeable activity occurring across the central meridian at latitudes below S25 during early afternoon on October 15. A partial halo CME was observed in LASCO images. The main part of the CME is not geoeffective, however, there is a chance that the northern flank could reach Earth on October 18. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to active on October 17 due to a coronal stream. A weak solar wind shock is possible on October 18 as a result of a filament eruption on October 15. 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) Data for all numbered solar regions according to the Solar Region Summary provided by SEC/NOAA. Comments are my own, as is data for regions not yet numbered and where the spot number is in parenthesis. Solar Date Spot Location region numbered count at Area Classification Comment midnight 10140 2002.10.04 2 S08W78 0140 HAX area near 0070 at midnight 10142 2002.10.05 N05W82 plage 2 spots observed at 10144 2002.10.07 1 N11W78 0060 HSX midnight, area was near 0020 then 6 spots observed at 10145 2002.10.08 2 N12W31 0080 HSX midnight, classification CSO 10146 2002.10.09 S09W70 plage 10147 2002.10.09 S03W53 plage 10148 2002.10.09 1 S20W22 0020 HSX 4 spots observed at midnight spot count includes spots in region S01. The southern and northern spot sections appear to be 2 separate bipolar 10149 2002.10.09 33 N14W20 0480 EAI regions, each without intermixed polarities. At midnight the southern group had 22 spots, the northern had 5. Including the spots of S01 the spot count would be 34. 10150 2002.10.09 S09W84 plage 10151 2002.10.09 S14W41 plage 10153 2002.10.10 S05W31 plage 10154 2002.10.10 12 S12W05 0050 CSO classification DSO at midnight 10156 2002.10.11 N09W56 plage 10157 2002.10.12 (4) N15W06 0010 AXX reemerged late on Oct.16 spot count appears to 10158 2002.10.12 4 S08E21 0120 CSO include those of region S03, only 1 HSX spot observed 10159 2002.10.13 5 S11E31 0190 CAO 10 spots observed at midnight 10160 2002.10.14 17 S20E28 0160 DAI 30 spots observed at midnight 10161 2002.10.15 5 N06W13 0030 CSO S01 emerged on (7) N19W20 0040 DAO 2002.10.14 S02 emerged on (4) S21E16 0010 BXO 2002.10.15 S03 emerged on (9) S04E25 0060 DAO beta-gamma 2002.10.15 S04 emerged on (1) S08E33 0010 HRX 2002.10.15 S05 visible on (1) N22E87 0220 HAX 2002.10.16 Total number of sunspots: 82 STAR spot count: 125 in 16 regions, spot number: 285 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) 2002.10 165.2 (1) 78.8 (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]