Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update January 23, 2000 at 05:05 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 minor storm on January 22. Solar wind speed ranged between 340 and 428 km/sec. A weak solar wind shock was observed at 00:23 UTC. Solar wind speed increased abruptly from 340 to 370 km/sec. Following the shock the interplanetary magnetic field gradually strengthened and swung strongly to very strongly southwards. A strong northward swing was observed after 02h UTC on January 23. Solar flare activity was moderate. Solar flux was 150.6, the planetary A index was 19 (3-hour Kp indices: 2224 4454, Boulder K indices: 2334 3443). Region 8829 was quiet and stable, the region will rotate over the west limb on Jan.24. Region 8831 decayed slowly, further M flares are unlikely. Region 8833 decayed losing all but one spot. Region 8835 reemerged with a single spot. Region 8836 once again decayed into spotless plage. Region 8837 decayed slowly and is rotating off the visible disk. Region 8838 decayed slowly and was quiet. Region 8839 developed further and could generate a minor M flare. Region 8840 was quiet and stable, as was region 8841. An active region is rotating into view at the northeast limb. Flares and CMEs 2 C flares and 1 M flare were recorded on January 22. The only flare of interest was produced by region 8831, an M1.0 flare at 18:01 UTC. The background x-ray flux is at the class B4 level. Coronal holes A large trans equatorial coronal hole is rotating around the east limb. it will rotate into a geoeffective position on January 25-29 and start a geomagnetic disturbance on January 28. Forecast The geomagnetic field is expected to be quiet to minor storm on January 23 and quit to unsettled on January 24-25. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally 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) Solar Date Actual no. Location at region numbered sunspots midnight Area Classification Comment 8828 20000111 S23W86 plage 8829 20000111 1 N16W72 0060 HSX 8831 20000112 4 S17W53 0110 DSO 8833 20000113 1 N18W38 0130 CSO 8835 20000115 1 N11W38 0000 AXX 8836 20000116 S13W28 plage 8837 20000118 4 S07W82 0370 EKO 8838 20000118 6 N12E14 0030 CAO 8839 20000120 11 N12W20 0060 DRO 8840 20000121 3 S24E09 0010 BXO 8841 20000121 5 S30E57 0060 CAO Total number of sunspots: 36 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 2000.01 167.4 (1) 108.0 (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]