Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update January 1, 2000 at 06:20 UTC. dxlc.com's IP address was changed without notice late on Dec.29. Unfortunately the name server crashed soon afterwards and most people were unable to access the site (even though it was being updated on a daily basis, as usual). Further technical problems prolonged the down time until late on Dec.31. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update December 2, 1999)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update December 2, 1999)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update December 2, 1999)] [Historical solar and geomagnetic data charts 1954-1999] [Experimental solar data chart January 1998-September 1999] Recent development The geomagnetic field was active to minor storm on December 31. Solar wind speed ranged between 567 and 728 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 130.1, the planetary A index was 27 (3-hour Kp indices: 4444 4445, Boulder K indices: 4444 4334). Region 8809 decayed slowly and was quiet, the region is spotless early on January 1. Region 8810 was mostly quiet and stable. Region 8812 was quiet and stable but is spotless early on Jan.1. Region 8813 was quiet and stable, as was region 8814. New region 8815 rotated into view just east of region 8814, the region is unstable and could produce C and perhaps minor M class flares. Flares and CMEs 2 C flares were recorded on December 31, the largest being an optically uncorrelated C2.7 flare at 18:56 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 unsettled to minor storm January 1-2 and quiet to active on January 3-4 due to a high speed coronal stream. 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 2 N24W20 0000 BXO 8810 19991224 16 N38W05 0330 FAO 8811 19991225 S30W89 plage 8812 19991229 1 S27W47 0000 AXX 8813 19991229 8 S17E38 0040 DRO 8814 19991229 2 N10E47 0130 HAX 8815 19991231 2 N10E61 0030 CRO Total number of sunspots: 31 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1998.11 140.1 74.0 73.0 (+2.5) 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 (92.5 predicted, +2.1) 1999.07 165.6 113.5 (94.0 predicted, +1.5) 1999.08 170.7 93.7 (98.9 predicted, +4.9) 1999.09 135.7 70.6 1999.10 164.8 116.4 1999.11 191.5 132.7 1999.12 169.8 (1) 122.3 (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]