Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update November 26, 1999 at 03:00 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 major storm on November 25. Solar wind speed ranged between 362 and 460 km/sec. Solar wind density was well above average most of the day. The interplanetary magnetic field was moderately strongly to strongly southwards 09-10:30 UTC at ACE. This resulted in an isolated major storm interval 09-12 UTC, severe storm was observed at a few high latitude stations. Solar flare activity was moderate. Solar flux was 183.7, the planetary A index was 18 (3-hour Kp indices: 1236 4332, Boulder K indices: 1236 3322). Region 8771 was mostly unchanged and could produce further major flares. Region 8772 was quiet and stable, as was region 8773. Region 8776 was quiet and stable. Region 8778 developed slowly early in the day. The region is still fairly unstable and could produce a minor M class flare. Regions 8779, 8780 and 8781 were quiet and stable. Flares and CMEs 8 C flares and 1 M flare were recorded on November 25. Region 8771 produced 4 C flares including a C7.4 flare at 17:17 UTC, and an M2.0/2N flare at 19:19 UTC. Region 8778 generated 3 C flares, the largest was a C5.2/1N event at 06:48 UTC. Region 8771 was the source of a major flare, an M5.7 long duration event at 01:23 UTC in November 26. Over the last day large coronal mass ejections have been observed off the northwest limb (probably related to an erupting prominence) and below the south pole (probably related to a backside flare or filament eruption). The background x-ray flux is at the class C1 level. Coronal holes An isolated coronal hole in the northern hemisphere was in 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 26. A weak coronal stream could influence the geomagnetic field today. 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 8769 991115 S12W55 plage 8771 991117 21 S15W51 0820 FKI beta-gamma 8772 991118 4 N07W20 0010 AXX 8773 991119 5 S15W39 0010 BXO 8774 991119 N20W09 plage 8776 991120 3 S28W42 0050 CSO 8777 991121 S27W12 plage 8778 991121 26 S14E10 0090 DSO 8779 991124 6 S09W44 0040 CSO 8780 991124 1 S11E38 0010 AXX 8781 991124 1 S13E58 0070 HSX Total number of sunspots: 67 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 196.1 (1) 174.9 (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]