Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update January 31, 2000 at 01:25 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 active on January 30. Solar wind speed ranged between 600 and 718 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 132.7, the planetary A index was 11 (3-hour Kp indices: 2232 3241, Boulder K indices: 2342 3231). Region 8841 decayed slowly and was quiet. Region 8845 was quiet and stable. Region 8847 was quiet and stable. Region 8848 could produce occasional C flares. Region 8849 was quiet and stable. New region 8850 emerged in the southeast quadrant. New region 8851 emerged in the northeast quadrant. Active regions are approaching the east limb (both northeast and southeast limbs) and should rotate into view within 2 days. Flares and CMEs Only a single C flare was observed on January 9. It was produced by region 8848 as a C2.2 long duration event The background x-ray flux is at the class B3 level. Coronal holes A large trans equatorial coronal hole was in a geoeffective position on January 25-31. Forecast The geomagnetic field is expected to be quiet to active January 31 to February 3. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally 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 8841 20000121 4 S30W47 0080 SAO 8843 20000123 N14W79 plage 8845 20000125 1 S16W84 0020 HSX 8846 20000126 N37W01 plage 8847 20000126 2 S25W84 0030 BXO 8848 20000126 5 S09E27 0070 CSO 8849 20000128 3 S17W06 0020 BXO 8850 20000129 3 S17W06 0020 BXO 8851 20000129 3 S17W06 0020 BXO Total number of sunspots: 20 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 2000.01 158.6 (8) 138.2 (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]