Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update November 24, 1999 at 02:50 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update 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 active on November 23. Solar wind speed ranged between 412 and 521 km/sec. A disturbance began early in the day. An increase in solar wind speed and a strengthening of the interplanetary magnetic field was observed at ACE near 06h UTC. Although no solar wind shock was observed solar wind parameters indicate that the source of the disturbance was a CME rather than a coronal stream. The IMF has strengthened further early on November 24. Solar flare activity was low. Solar flux was 185.6, the planetary A index was 15 (3-hour Kp indices: 1344 3334, Boulder K indices: 1443 3333). Region 8765 is rotating off the visible disk. The region was quiet but has some potential for significant flare activity over the next 2 days while at and just behind the west limb. Region 8766 decayed further and was quiet. Region 8768 will rotate behind the west limb early today. Region 8771 more than doubled its areal coverage but gained only a couple of spots. The region is less magnetically complex than it was a couple of days ago, but still has the potential to produce a major flare. Region 8772 was quiet and stable, as was region 8773. Region 8776 decayed slowly and was quiet. Region 8777 was quiet and stable. Region 8778 was mostly quiet and stable. Flares and CMEs 5 C flares were recorded on November 23. Region 8771 produced 3 C flares, none of them larger than C2.0. The background x-ray flux is at the class C1 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 unsettled to active on November 24 with a chance of minor storm intervals. A weak coronal stream could influence the geomagnetic field on November 26. 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 Location region numbered no. at Area Classification Comment sunspots midnight 8765 991111 9 S12W85 0330 EKC beta-gamma-delta 8766 991113 11 N18W63 0040 ESO 8768 991114 4 N17W89 0060 CSO 8769 991115 S12W29 plage 8771 991117 26 S14W26 0650 EKC beta-gamma 8772 991118 3 N06E04 0020 CSO 8773 991119 4 S15W15 0010 CSO 8774 991119 N20E17 plage 8775 991119 S16W70 plage 8776 991120 5 S28W14 0040 DAO 8777 991121 1 S27E14 0030 HSX 8778 991121 4 S16E36 0040 CAO 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 197.1 (1) 164.8 (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]