Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update November 17, 1999 at 01:30 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 16 with minor storm intervals observed at high latitudes. Solar wind speed is unavailable (until approx. Nov.19 due to the Leonids). A CME based disturbance arrived early in the day causing the interplanetary magnetic field to swing moderately strongly to strongly southwards for several hours. The source of the disturbance is likely a coronal mass ejection associated with the long duration M class event in region 8759 on November 12. Solar flare activity was high. Solar flux was 233.4, the planetary A index was 16 (3-hour Kp indices: 1124 4433, Boulder K indices: 1124 3331). Region 8755 was quiet and stable, it will rotate over the west limb on November 18. Region 8759 was mostly unchanged and could produce further M class flares. Region 8760 will rotate off the visible disk today but could produce another M flare over the next couple of days. Region 8763 decayed and was quiet. Region 8765 developed further and is a very complex region capable of producing a major proton flare. Region 8766 developed further as well and is a complex region which has major flare potential. Region 8767 was quiet and stable. Region 8768 developed quickly early in the day and could produce another minor M flare. Region 8769 was quiet and stable. New region 8770 emerged in the southwest quadrant. Flares and CMEs 5 C flares and 7 M flares (the highest number of M flares in a single day during solar cycle 23) were recorded on November 16. Region 8759 produced a long duration M2.3 event peaking at 07:10 UTC (NOAA/SEC attributed this flare to region 8765. While that region did produce a flare at 06:22 UTC, that flare was much smaller than the event in region 8759). Region 8760 generated an impulsive M3.0/SN flare at 04:10 UTC. A coronal mass ejection was observed off the west limb. Region 8765 was the source of a long duration M1.4/1N event peaking at 14:11 UTC and an M2.0/1N event at 21:24 UTC. Region 8766 produced an M3.8/1B flare at 02:46 UTC. It was accompanied by a strong type II sweep and a moderately strong type IV sweep. The associated coronal mass ejection was a partial halo one covering most of the east limb and the north pole. There is a chance this CME could impact the earth on November 19. Region 8766 was the source of an M1.8 flare at 05:12 UTC. It was accompanied by a moderately strong type II sweep. Region 8768 generated an M1.0/SN flare at 09:22 UTC. Apart from the two CMEs mentioned above, several other CMEs are likely to have been generated in association with the other M class events. There is a fairly high probability that at least one of the CMEs will impact the earth on November 19. The background x-ray flux is at the class C1-C2 level. Coronal holes A small coronal hole in the southern hemisphere was in a geoeffective position on November 14-15. Forecast The geomagnetic field is expected to be quiet to aqctive on November 17, possibly with isolated minor storm intervals. A coronal stream could influence the field on November 17-18. A coronal mass ejection observed on November 14 could reach earth on November 17. If there is an impact, active to major storm would be likely. 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 Location region numbered no. at Area Classification Comment sunspots midnight 8755 991105 1 N22W72 0070 HSX 8758 991106 N18W65 plage 8759 991106 34 N12W45 0200 FAI beta-gamma 8760 991107 10 N15W83 0450 EKO 8761 991108 N20W54 plage 8763 991110 4 S13W07 0040 CSO 8765 991111 38 S12E06 0930 EKC beta-gamma-delta 8766 991113 20 N18E31 0330 EKC beta-gamma-delta 8767 991114 6 N42W54 0020 CSO 8768 991114 12 N17E05 0090 DAO 8769 991115 1 S10E65 0080 HAX 8770 991116 5 S14W23 0040 DSO Total number of sunspots: 131 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 193.3 (1) 116.9 (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]