Solar Terrestrial Activity Report [Image] Last update October 22, 2002 at 04:10 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 unsettled on October 21. Solar wind speed ranged between 470 and 710 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 182.5, the planetary A index was 11 (STAR Ap - based on the mean of three hour ap indices: 12.1). Three hour interval K indices: 23323333 (planetary), 23322322 (Boulder). The background x-ray flux is at the class C1 level. At midnight there were 6 spotted regions on the visible disk, 1 of which has not yet been numbered. A total of 15 C class events were recorded during the day. Spotless region 10154 generated a C3.6 flare at 04:19 UTC. Region 10149 decayed further and rotated quietly out of view. Region 10158 was quiet and stable. Please observe that SEC has included the spots of S03 (see below) in this region. Region 10159 decayed quickly and had only a few tiny spots left by midnight. The region could become spotless today. Region 10160 decayed significantly losing many spots including all trailing spots. The region has simplified and further decay is likely. Flares: C3.3 at 00:57 and C6.6 at 21:13 UTC. Region 10162 decayed slightly losing some spots and penumbral area between the dominant leading and trailing penumbrae. There is no distinct magnetic delta structure anymore. M class flares are likely. Flares: C3.1 at 05:23, C2.3 at 08:36, C3.7 at 12:27, C1.7 at 15:05 and C4.7 at 23:58 UTC Region 10164 developed early in the day, then decayed quickly after noon and was spotless by midnight. Region 10165 developed slowly. 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. Having had only small spots left early on Oct.21, two of the spots developed penumbra during the day. Location at midnight: S05W45. Coronal mass ejections (CMEs) October 19-21: No obviously geoeffective CMEs were observed. Coronal holes A large coronal hole in the southern hemisphere will be in a geoeffective position on October 21-24 and is likely to cause unsettled to minor geomagnetic storm conditions on October 24-27. Forecast The geomagnetic field is expected to be quiet to unsettled on October 22-23. Quiet to minor storm is likely on October 24-26 due to a coronal stream. 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 10148 2002.10.09 S21W87 plage 10149 2002.10.09 3 N14W88 0080 DAO rotated out of view 10154 2002.10.10 S14W75 plage 10157 2002.10.12 N15W71 plage SEC spot count includes those of 10158 2002.10.12 4 1 S08W47 0060 CSO region S03. This is an HSX group. Position was S09W47 at midnight. classification was BXO 10159 2002.10.13 7 4 S13W35 0030 DSO at midnight with an area of 0010. 10160 2002.10.14 16 15 S22W40 0080 EAO classification was DAO at midnight 10161 2002.10.15 N06W78 plage 10162 2002.10.17 32 48 N26E34 0920 FKI beta-gamma 10163 2002.10.18 S21W49 plage 10164 2002.10.20 3 N11E40 0010 BXO now spotless 10165 2002.10.20 4 6 N21E58 0240 CAO classification DAO at midnight S03 emerged on 4 S05W45 0030 DAO 2002.10.15 S06 emerged on N24W23 plage 2002.10.19 Total spot count: 69 78 SSN: 139 138 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) 2002.10 168.4 (1) 107.5 (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]