Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update November 22, 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 unsettled on November 21. Solar wind speed ranged between 351 and 475 km/sec. Wind speed decreased gradually until just after noon, then a fairly complicated pattern was observed for the remainder of the day. Generally wind speed increased to nearly 500 km/sec early on November 22. The source of the wind speed fluctuations could be the interaction between an arriving coronal stream and the trailing outer edges of a CME which has at times influenced the field over the last couple of days. The interplanetary magnetic field is quite strong early on Nov.22 and has a strong northerly orientation. Should any significant southerly excursions occur, the geomagnetic field could see isolated periods of minor storming. Solar flare activity was moderate. Solar flux was 210.1, the planetary A index was 10 (3-hour Kp indices: 2232 1333, Boulder K indices: 1452 1333). Region 8765 is decaying slowly. The region is still large and complex and could produce a major flare before rotating off the visible disk on November 24. Region 8766 decayed further and was quiet. Occasional C class flares are possible. Region 8768 was unstable most of the day. The region could produce further C flares, a minor M flare is not unlikely. Region 8769 decayed into spotless plage. Region 8771 developed slowly and has major flare potential. Region 8772 was quiet and stable, as was region 8773. Region 8774 decayed into spotless plage, as did region 8775. Region 8776 developed slowly and should be capable of C class flaring. New region 8777 emerged in the southeast quadrant. New region 8778 rotated into view at the southeast limb. Neither of the new regions are impressive and could become spotless in a day or two. Flares and CMEs 2 C flares and 3 M flares were recorded on November 21. Region 8768 produced the only optically correlated C flare. November 20: Region 8771 generated an M3.2/2N flare at 22:35 UTC. It was accompanied by a moderately strong type II sweep and a weak type IV sweep. The associated coronal mass ejection could impact Earth on November 23 and cause active to major storm conditions. The background x-ray flux is at the class C1 level. Coronal holes An isolated coronal hole in the southern hemisphere was in a geoeffective position on November 19-20. An isolated coronal hole in the northern hemisphere will be in a geoeffective position November 22-23. Forecast The geomagnetic field is expected to be quiet to active on November 22 under the influence of a coronal stream. A CME could impact Earth on November 23 and cause active to major storm conditions. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally fair. 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 8763 991110 S13W74 plage 8765 991111 25 S12W60 0790 EKC beta-gamma-delta 8766 991113 14 N18W36 0120 DAO 8768 991114 9 N16W65 0080 CSO 8769 991115 S12W03 plage 8771 991117 32 S16E01 0220 EAI beta-gamma-delta 8772 991118 8 N04E29 0020 CSO 8773 991119 6 S15E12 0020 BXO 8774 991119 N20E43 plage 8775 991119 S16W44 plage 8776 991120 12 S30E08 0020 DSO 8777 991121 2 S26E40 0010 AXX 8778 991121 2 S14E62 0010 BXO Total number of sunspots: 110 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 197.9 (1) 153.6 (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]