Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update November 25, 1999 at 04:20 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update November 2, 1999)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update November 2, 1999)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update November 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 minor storm on November 24. Solar wind speed ranged between 395 and 494 km/sec. Solar wind density was well above average most of the day. Major storming was observed at high latitudes 08-11 UTC. Solar flare activity was moderate. Solar flux was 186.7, the planetary A index was 19 (3-hour Kp indices: 2345 3331, Boulder K indices: 2245 4331). Region 8765 rotated off the visible disk. Region 8766 decayed further and was quiet. The region will rotate off the visible disk today. Region 8771 developed further and is capable of producing a major flare. Region 8772 was quiet and stable, as was region 8773. Region 8776 developed slowly and was quiet. Region 8777 decayed into spotless plage. Region 8778 developed quickly during the second half of the day and could produce further minor M flares. A major flare could become possible should further development occur. New region 8779 emerged in the southwest quadrant. New region 8780 rotated into view at the southeast limb. New region 8781 rotated partly into view at the southeast limb Flares and CMEs 10 C flares and 2 M flares were recorded on November 24. Region 8771 produced 3 C flares and an M3.0 flare at 2337 UTC. Region 8778 was the source of 4 C flares and an impulsive M2.2/1B flare at 21:56 UTC. An optically uncorrelated C9.6 flare was observed at 12:22 UTC. The background x-ray flux is at the class B8 level. Coronal holes An isolated coronal hole in the northern hemisphere was a geoeffective position on November 23. A well defined coronal hole in the northern hemisphere will reach the central meridian on November 27, however, it may be located too far to the north to be geoeffective. Forecast The geomagnetic field is expected to be quiet to unsettled on November 25. A weak coronal stream could influence the geomagnetic field on November 25-26. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally 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 8765 991111 1 S13W98 0060 HAX 8766 991113 3 N18W76 0010 BXO 8769 991115 S12W42 plage 8771 991117 18 S15W40 0750 EKI beta-gamma 8772 991118 3 N06W08 0010 AXX 8773 991119 4 S15W27 0010 BXO 8774 991119 N20E04 plage 8775 991119 S16W83 plage 8776 991120 6 S28W29 0080 EAO 8777 991121 S27E01 plage 8778 991121 16 S15E23 0080 CAO 8779 991124 2 S09W27 0010 BXO 8780 991124 3 S11E51 0030 CSO 8781 991124 1 S13E71 0050 HAX Total number of sunspots: 57 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 9809 138.3 92.9 69.5 (+1.7) 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 predicted, +5.0) 9906 169.8 137.7 (94.6 predicted, +4.2) 9907 165.6 113.5 (99.6 predicted, +5.0) 9908 170.7 93.7 9909 135.7 70.6 9910 164.8 116.4 9911 196.7 (1) 170.0 (2) 1) Running average based on the daily 20:00 UTC solar flux value at 2800 MHz.. 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]