Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update January 20, 2000 at 04:45 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update January 1, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update January 1, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update January 1, 2000)] [Historical solar and geomagnetic data charts 1954-1999] [Experimental solar data chart January 1998-September 1999] Recent development The geomagnetic field was quiet to slightly unsettled on January 19. Solar wind speed ranged between 272 and 383 km/sec. A very minor solar wind shock was observed at 13:05 UTC at ACE with an abrupt jump in solar wind speed from 280 to 315 km/sec. Geomagnetic activity increased only slightly following this shock. At 22:07 UTC another solar wind shock was observed, this time the wind speed increased from 320 to 370 km/sec. Since then the interplanetary magnetic field has been mostly weakly southwards. The latter shock may have been associated with a CME from a filament eruption on January 16. Solar flare activity was low. Solar flux was 178.6, the planetary A index was 4 (3-hour Kp indices: 0000 0223, Boulder K indices: 0100 1222). Region 8821 was quiet and stable, the region will rotate over the west limb early today. Region 8824 decayed further and is unlikely to produce other than occasional C flares. Regions 8828 and 8829 decayed further and were quiet. Region 8830 developed slowly and will rotate off the visible disk on January 21. Region 8831 was mostly unchanged and could produce further M class events. Region 8832 was quiet and stable, the region will rotate over the west limb today. Region 8833 was mostly unchanged and could gnerate further C flares. Region 8835 reemerged with a single spot. Region 8836 was quiet and stable. Region 8837 developed further but at a much slower pace than on the previous day. C flares are possible. Region 8838 was quiet and stable. Flares and CMEs 5 C flares were recorded on January 19. Regions 8824, 8829 and 8833 produced one C flare each, none of them of particular interest. January 18: Region 8831 was the source of a long duration M3.9/1N event peaking at 17:27 UTC. This flare was associated with moderately strong type II and IV sweeps and a full halo coronal mass ejection. The CME will likely impact Earth sometime on January 21 or 22 and cause unsettled to major storm conditions. The background x-ray flux is at the class B7 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled with on January 20 with a fair possibility of active intervals. Geomagnetic activity could increase to unsettled to major storm on January 21 or 22 if the CME mentioned above impacts Earth. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally fair. 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) Solar Date Actual no. Location at region numbered sunspots midnight Area Classification Comment 8821 20000106 1 N26W88 0070 HAX 8823 20000108 S32W79 plage 8824 20000109 12 S13W57 0070 CSO 8825 20000110 N11W56 plage 8828 20000111 5 S23W47 0010 BXO 8829 20000111 4 N16W32 0060 CSO 8830 20000112 3 S15W73 0010 BXO 8831 20000112 23 S18W12 0200 EAO 8832 20000113 1 S15W81 0000 AXX 8833 20000113 8 N17E02 0160 CSO 8835 20000115 1 N08E02 0010 AXX 8836 20000116 2 S13E12 0000 AXX 8837 20000118 10 S09W42 0100 DSO 8838 20000118 6 N12E53 0080 CAO Total number of sunspots: 76 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1998.12 150.1 81.9 77.9 (+4.9) 1999.01 140.6 62.0 82.6 (+4.7) 1999.02 141.9 66.3 84.6 (+2.0) 1999.03 126.3 68.8 83.8 (-0.8) 1999.04 117.2 63.7 85.4 (+1.6) 1999.05 148.4 106.4 90.4 (+5.0) 1999.06 169.8 137.7 93.0 (+2.6) 1999.07 165.6 113.5 (94.8 predicted, +1.8) 1999.08 170.7 93.7 (99.4 predicted, +4.6) 1999.09 135.7 70.6 (105.7 predicted, +6.3) 1999.10 164.8 116.4 1999.11 191.5 132.7 1999.12 169.8 86.4 2000.01 168.6 (1) 95.5 (2) 1) Running average based on the daily 20:00 UTC solar flux measurement at 2800 MHz by DRAO. 2) Unofficial, accumulated value. The official value is typically 25-40% 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 in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]