Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update January 27, 2000 at 06:20 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 predominantly quiet on January 26 with a single slightly active interval 03-06h UTC. Solar wind speed ranged between 344 and 382 km/sec. A disturbance may have started as a significant strengthening of the interplanetary magnetic field was observed at ACE just after 05h UTC on Jan.27. Solar flare activity was low. Solar flux was 140.7, the planetary A index was 7 (3-hour Kp indices: 2420 1222, Boulder K indices: 2431 2112). Region 8833 was quiet and has rotated over the west limb early on Jan.27. Region 8839 was quiet and stable and will rotate over the west limb today. Region 8840 was quiet and stable. Region 8841 decayed slowly and was quiet. Region 8842 decayed slowly and was quiet. Region 8843 was quiet and stable. Region 8844 developed further and is likely to produce C flares, an isolated minor M flare is possible. Region 8845 developed slowly and could produce further C flares. New region 8846 emerged in the northeast quadrant. New region 8847 emerged in the southwest quadrant. New region 8848 rotated partly into view at the southeast quadrant. Flares and CMEs 4 C flares were recorded on January 26, none of them exceeding the C1 level. A filament eruption was observed in the southern hemisphere near region 8841, there is a chance a CME from this event could impact Earth. The background x-ray flux is at the class B3 level. Coronal holes A large trans equatorial coronal hole will rotate into a geoeffective position on January 25-30. Forecast The geomagnetic field is expected to be quiet to active on January 27. A coronal stream related disturbance will start late on January 27 or on January 28 and continue until February 2. Quiet to active is expected most of the time with periods of minor storming 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 no. Location at region numbered sunspots midnight Area Classification Comment 8833 20000113 1 N20W88 0120 HSX 8836 20000116 S13W80 plage 8838 20000118 N12W41 plage 8839 20000120 1 N14W78 0000 AXX 8840 20000121 1 S25W50 0000 AXX 8841 20000121 5 S30E05 0150 CSO 8842 20000123 6 S17W52 0020 BXO 8843 20000123 1 N14W27 0000 AXX 8844 20000124 16 N04W47 0210 DAI 8845 20000125 6 S15E09 0040 CAO 8846 20000126 2 N37E51 0000 AXX 8847 20000126 1 S26W28 0000 AXX 8848 20000126 1 S07E78 0010 AXX Total number of sunspots: 41 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 2000.01 163.2 (1) 126.1 (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]