Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update January 24, 2000 at 04:50 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 23. Solar wind speed ranged between 349 and 441 km/sec. Solar flare activity was very low. Solar flux was 140.5, the planetary A index was 25 (3-hour Kp indices: 5524 4322, Boulder K indices: 4523 4321). Region 8829 was quiet and stable and will rotate off the visible disk today. Region 8831 was quiet and stable, as was region 8833. Region 8835 once again decayed into spotless plage. Region 8837 rotated over the west limb. Region 8838 decayed slowly and was quiet. Region 8839 did not change significantly and was quiet. Region 8840 was quiet and stable, as was region 8841. New region 8842 emerged in the southwest quadrant. New region 8843 emerged in the northeast quadrant. Flares and CMEs There was no flare activity on January 23. The background x-ray flux is at the class B3-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 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 8829 20000111 1 N16W86 0050 HSX 8831 20000112 4 S17W67 0090 CSO 8833 20000113 1 N18W51 0110 HSX 8835 20000115 N11W51 plage 8836 20000116 S13W41 plage 8837 20000118 1 S08W91 0190 HRX 8838 20000118 4 N12E00 0020 CSO 8839 20000120 11 N11W34 0060 DSO 8840 20000121 3 S24W06 0020 DSO 8841 20000121 4 S29E43 0080 CSO 8842 20000123 3 S17W10 0010 BXO 8843 20000123 3 N14E14 0010 BXO Total number of sunspots: 35 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 2000.01 166.3 (1) 112.4 (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]