Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update January 21, 2000 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 January 1, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update January 1, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update January 1, 2000)] [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 January 20. Solar wind speed ranged between 359 and 420 km/sec. The interplanetary magnetic field was mostly moderately southwards. Solar flare activity was low. Solar flux was 170.7, the planetary A index was 10 (3-hour Kp indices: 2133 3332, Boulder K indices: 2134 3332). Region 8824 decayed further and was quiet. The region will rotate over the west limb on January 22. Region 8828 decayed into spotless plage. Region 8829 was quiet and stable. Region 8830 rotated off the visible disk. Region 8831 was mostly unchanged and could produce isolated M class events. Region 8833 was mostly unchanged and could generate C flares. Region 8835 once again decayed into spotless plage. Region 8836 decayed into spotless plage. Region 8837 developed further and has M class flaring potential. Region 8838 was quiet and stable. New region 8839 emerged in the northeast quadrant near the central meridian. Flares and CMEs 4 C flares were recorded on January 20. All flares were optically unaccounted with the largest event being a C4.1 flare at 02:26 UTC. January 18: Region 8831 was the source of a long duration M3.9/1N event peaking at 17:27 UTC. This flare was associated with moderately strong type II and IV sweeps and a full halo coronal mass ejection. The CME will likely impact Earth sometime on January 21 or 22 and cause unsettled to major storm conditions. The background x-ray flux is at the class C1 level. Coronal holes A large trans equatorial coronal hole is rotating around the east limb. The southern part could rotate into a geoeffective position on January 25 and start a geomagnetic disturbance on January 28. Forecast The geomagnetic field is expected to be quiet to active on January 21. Geomagnetic activity could increase to unsettled to major storm on January 21 or 22 if the CME mentioned above impacts Earth. 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 no. Location at region numbered sunspots midnight Area Classification Comment 8824 20000109 5 S13W72 0020 CRO 8825 20000110 N11W69 plage 8828 20000111 S23W60 plage 8829 20000111 1 N17W45 0070 HSX 8831 20000112 18 S18W25 0210 EAO 8833 20000113 9 N17W11 0170 CSO 8835 20000115 N08W11 plage 8836 20000116 S13W01 plage 8837 20000118 9 S08W55 0220 DSO 8838 20000118 5 N12E40 0070 CAO 8839 20000120 2 N11E06 0010 BXO Total number of sunspots: 49 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1998.12 150.1 81.9 77.9 (+4.9) 1999.01 140.6 62.0 82.6 (+4.7) 1999.02 141.9 66.3 84.6 (+2.0) 1999.03 126.3 68.8 83.8 (-0.8) 1999.04 117.2 63.7 85.4 (+1.6) 1999.05 148.4 106.4 90.4 (+5.0) 1999.06 169.8 137.7 93.0 (+2.6) 1999.07 165.6 113.5 (94.8 predicted, +1.8) 1999.08 170.7 93.7 (99.4 predicted, +4.6) 1999.09 135.7 70.6 (105.7 predicted, +6.3) 1999.10 164.8 116.4 1999.11 191.5 132.7 1999.12 169.8 86.4 2000.01 168.7 (1) 99.3 (2) 1) Running average based on the daily 20:00 UTC solar flux measurement at 2800 MHz by DRAO. 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]