Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update November 21, 1999 at 03:55 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 20. Solar wind speed ranged between 409 and 528 km/sec. The weak grazing solar wind shock observed just before midnight on November 19 caused no significant increase in geomagnetic activity. Although solar wind speed initially increased, a gradual decrease was observed within a few hours. Solar wind density was above average most of the day. ACE EPAM data additionally indicate the presence of a large disturbance near the earth and that only the outer edge of it came close enough early in the day to be observed directly at ACE. Solar flare activity was moderate. Solar flux was 204.3, the planetary A index was 9 (3-hour Kp indices: 3322 2222, Boulder K indices: 4323 1221). Region 8765 is decaying slowly. The region is still large and complex and could produce a major flare before rotating off the visible disk in about 4 days. Region 8766 decayed slowly and appears unlikely to produce other than occasional C and minor M class flares. Region 8768 decayed slowly and was mostly quiet. The region has become more unstable early on November 21. Region 8769 decayed slowly and was quiet. Region 8770 was quiet and stable and will rotate over the west limb today. Region 8771 developed further and now has a magnetic delta configuration. The region should be capable of producing a major flare. Region 8772 was quiet and stable, as was region 8773. Region 8774 was quiet and has become spotless early on November 21. Region 8775 was quiet and stable, the region is spotless early on November 21. New region 8776 emerged in the southeast quadrant. Flares and CMEs 5 C flares and 1 M flare were recorded on November 20. Region 8768 produced the only optically correlated C flare. 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 unsettled to major storm conditions. Region 8765 produced an M1.3/1N flare at 00:14 UTC on November 21. 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. Forecast The geomagnetic field is expected to be quiet to unsettled on November 21. A coronal stream could reach Earth on November 22-23 and cause unsettled to active intervals. A CME could impact Earth on November 23 and cause unsettled 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 S13W61 plage 8765 991111 36 S13W47 0910 EKC beta-gamma-delta 8766 991113 26 N18W25 0180 EAI beta-gamma 8768 991114 5 N17W54 0120 CSO 8769 991115 3 S12E10 0020 CSO 8770 991116 7 S13W80 0060 CSO 8771 991117 20 S17E12 0180 DAI beta-gamma-delta 8772 991118 4 N04E42 0030 CSO 8773 991119 5 S16E25 0030 CSO 8774 991119 3 N20E56 0010 BXO 8775 991119 1 S16W31 0000 AXX 8776 991120 5 S31E24 0030 CSO Total number of sunspots: 115 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 197.3 (1) 146.9 (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]