Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update December 11, 1999 at 03:25 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update 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 quiet to unsettled on December 10. Solar wind speed ranged between 455 and 570 km/sec. Solar flare activity was low. Solar flux was 164.4, the planetary A index was 7 (3-hour Kp indices: 2322 2232, Boulder K indices: 2331 3222). Region 8785 decayed slowly and was quiet. Region 8787 was quiet and stable. the region appears to be spotless early on Dec.11. Region 8788 was quiet and decayed slowly. Region 8790 developed slowly and was quiet. Region 8791 decayed and was quiet, the region is spotless early on Dec.11. Region 8792 was mostly quiet and stable. Region 8793 decayed and was quiet. Region 8794 was quiet and stable. New region 8795 emerged in the southeast quadrant near region 8793. It developed rapidly during the first half of the day before relaxing somewhat during the second half of the day. A couple of active regions at low latitudes are at the east limb and will rotate into view today and tomorrow. Flares and CMEs 3 C flares were recorded on December 10. Region 8792 generated a C3.7 flare at 02:10 UTC. The background x-ray flux is at the class B5 level. Coronal holes A small trans equatorial coronal hole was in a geoeffective position on December 10-11.. Forecast The geomagnetic field is expected to be quiet to unsettled on December 11-12. Unsettled to active is possible on December 13-14 due to a coronal stream. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally fair to 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 8785 991201 1 N15W48 0100 HSX 8787 991202 3 N13W63 0010 BXO 8788 991202 12 N11W23 0460 FHO 8790 991206 14 N12W07 0090 DAO 8791 991207 1 S15E22 0000 AXX 8792 991208 3 N17E43 0060 CAO 8793 991209 1 S16W04 0020 HSX 8794 991209 1 S14E44 0030 HSX 8795 991210 4 S12E06 0070 DAO Total number of sunspots: 40 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 9810 117.2 55.5 70.5 (+1.0) 9811 140.1 74.0 73.0 (+2.5) 9812 150.1 81.9 77.9 (+4.9) 9901 140.6 62.0 82.6 (+4.7) 9902 141.9 66.3 84.6 (+2.0) 9903 126.3 68.8 83.8 (-0.8) 9904 117.2 63.7 85.4 (+1.6) 9905 148.4 106.4 90.4 (+5.0) 9906 169.8 137.7 (93.6 predicted, +3.2) 9907 165.6 113.5 (96.9 predicted, +3.3) 9908 170.7 93.7 (102.8 predicted, +5.9) 9909 135.7 70.6 9910 164.8 116.4 9911 191.5 132.7 9912 153.9 (1) 33.4 (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]