Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update January 5, 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 active on January 4. Solar wind speed ranged between 503 and 626 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 134.7, the planetary A index was 12 (3-hour Kp indices: 1233 4323, Boulder K indices: 1324 3223). Region 8810 decayed slowly. Further C class flares are possible. Region 8813 was mostly unchanged and could produce occasional C flares. Region 8814 decayed slowly. Region 8815 decayed slowly and was quiet. New region 8816 emerged in the northwest quadrant. New region 8817 emerged in the northeast quadrant. Both new regions have been developing fairly quickly and could soon become capable of C class flaring. Flares and CMEs Only 2 C flares were recorded on January 4. Region 8810 generated a C2.0 flare at 11:14 UTC and a C1.1 flare at 14:28 UTC. The background x-ray flux is at the class B3 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on January 5-6, possibly with isolated active intervals. 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 8809 19991224 N24W72 plage 8810 19991224 3 N38W51 0170 FSO 8813 19991229 12 S16W20 0140 DSO 8814 19991229 2 N12W06 0020 HAX 8815 19991231 14 N10E11 0020 BXO 8816 20000104 6 N23W15 0020 CRO 8817 20000104 5 N24E10 0010 CRO Total number of sunspots: 42 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 2000.01 132.7 (1) 10.2 (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]