Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update January 2, 2000 at 03:50 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 1. Solar wind speed ranged between 641 and 741 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 129.9, the planetary A index was 27 (3-hour Kp indices: 5544 5332, Boulder K indices: 5543 4332). Region 8809 decayed into spotless plage. Region 8810 decayed slowly and was quiet. Region 8812 decayed into spotless plage. Region 8813 was quiet and stable, as were regions 8814 and 8815. Flares and CMEs 3 C flares were recorded on January 1, the largest being an optically uncorrelated C3.1 flare at 01:20 UTC. 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 December 28 - January 1. Forecast The geomagnetic field is expected to be quiet to active on January 2-4 with a chance of isolated minor storm 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 N24W33 plage 8810 19991224 11 N38W18 0270 FAO 8812 19991229 S27W60 plage 8813 19991229 6 S17E21 0050 DSO 8814 19991229 3 N10E34 0180 HHX 8815 19991231 9 N10E48 0040 CRO Total number of sunspots: 29 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 2000.01 129.9 (1) 2.2 (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]