Solar Terrestrial Activity Report [Image] Last update October 23, 2002 at 02:10 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 active on October 22. Solar wind speed ranged between 441 and 565 km/sec. Solar flare activity was moderate. Solar flux was 169.4, the planetary A index was 12 (STAR Ap - based on the mean of three hour ap indices: 13.5). Three hour interval K indices: 32143333 (planetary), 22142332 (Boulder). The background x-ray flux is at the class B7 level. At midnight there were 5 spotted regions on the visible disk, 1 of which has not yet been numbered. A total of 5 C and 1 M class events were recorded during the day. Region 10158 decayed slowly and quietly. There was a single penumbra one day earlier, this has now split into two penumbrae. Please observe that SEC has included the spots of S03 (see below) in this region. Region 10159 decayed further. Several tiny spots could be observed until early evening, no spots were visible at midnight. Region 10160 decayed further and had only a few small spots left by the end of the day. At the current rate of decay this region will become spotless later today or tomorrow. Region 10162 was mostly unchanged. Some decrease in penumbral area was noticed in the northeastern part of the trailing spots. There is a weak magnetic delta structure in the northwestern part of the trailing spots. M class flares are possible. Flares: C2.4 at 04:15 and M1.0 at 15:35 UTC. Region 10164 was spotless all day in all available images. Region 10165 gained a few small spots. C and minor M class flares are possible. Spotted regions which have not yet been numbered: 1. [S03] A region emerged in the southeast quadrant northeast of region 10158 on October 15. The region developed slowly until October 18. Slow decay was observed on October 19. On October 20 the region decayed quickly. Slow development was observed on October 21 and 22. Location at midnight: S06W62. Flares: C1.8 at 05:19, C1.6 at 12:29, C2.2 at 12:48 and C1.3 at 22:28 UTC. Coronal mass ejections (CMEs) October 20-22: No obviously geoeffective CMEs were observed. Coronal holes A large and well defined coronal hole in the southern hemisphere will be in a geoeffective position on October 21-24. Forecast The geomagnetic field is expected to be quiet to unsettled on October 23. Quiet to minor storm is likely on October 24-26 due to a coronal stream, isolated major storm intervals are possible during the first day after the onset of this disturbance. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to 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 10154 2002.10.10 S14W88 plage 10157 2002.10.12 N15W84 plage SEC spot count includes those of region S03. This is 10158 2002.10.12 7 3 S08W61 0120 DSO an HSX group. Position was S09W58 at midnight, area was 0050 then. 10159 2002.10.13 3 S15W46 0010 BXO now spotless 10160 2002.10.14 13 10 S20W56 0110 DAO area was 0030 at midnight beta-gamma-delta 10162 2002.10.17 34 45 N27E22 1100 EKI classification should be FKI 10163 2002.10.18 S21W62 plage 10164 2002.10.20 3 N11E25 0010 BXO spotless all day in all available images 10165 2002.10.20 12 10 N21E46 0260 CKO beta-gamma S03 emerged on 5 S05W62 0050 DAO 2002.10.15 S06 emerged on N24W36 plage 2002.10.19 Total spot count: 72 73 SSN: 132 123 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) 2002.10 168.5 (1) 111.7 (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]