Solar Terrestrial Activity Report [Image] Last update January 17, 2001 at 05:10 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 2, 2001) - Has cycle 23 peaked?] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update January 2, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update January 2, 2001)] [Historical solar and geomagnetic data charts 1954-2000 (last update October 20, 2000)] Recent development The geomagnetic field was quiet to unsettled on January 16. Solar wind speed ranged between 327 and 386 km/sec. Solar flare activity was low. Solar flux was 161.9, the planetary A index was 6 (3-hour K indices: 0022 3232, Boulder K indices: 1022 3110). Regions 9301 and 9302 decayed into spotless plage. Region 9304 was quiet and stable and will rotate off the visible disk on January 18. Region 9306 decayed and was mostly quiet. A minor M class flare is possible. Region 9308 decayed slowly and was quiet. Region 9309 decayed into spotless plage. Region 9310 decayed slowly and was quiet, the region is spotless early on January 17. Region 9311 was quiet and stable. New region 9312 rotated into view at the northeast limb. Flares and CMEs A total of 6 C class events were recorded on January 16. Region 9306 produced a C2.2 flare at 06:11 UT. January 14: A huge filament in the northern hemisphere stretching from near the central meridian, across the northwest quadrant to behind the northwest limb erupted. The eruption started at 06:24 UT and resulted in a large partial halo coronal mass ejection above the northeast limb (partially), the north pole and the northwest limb. There is a small chance of a minor terrestrial CME impact on January 17. The background x-ray flux is at the class B5 level. Coronal holes Two very small coronal holes in the southern hemisphere will rotate into a geoeffective position on January 17-18. Any coronal stream originating from these holes is unlikely to influence the geomagnetic field to a significant degree. Forecast The geomagnetic field is expected to be quiet to unsettled on January 17 with a chance of active intervals on Jan.17 should the CME described above reach Earth. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 no. Location at region numbered sunspots midnight Area Classification Comment 9301 2001.01.04 N08W86 plage 9302 2001.01.05 N19W82 plage 9304 2001.01.07 1 N11W70 0020 HSX 9305 2001.01.07 S06W56 plage 9306 2001.01.08 28 N11W53 0330 EAI beta-gamma 9308 2001.01.10 16 N14W28 0100 DAO 9309 2001.01.11 N10W77 plage 9310 2001.01.14 1 N26E22 0000 AXX 9311 2001.01.15 7 N04E36 0030 CSO 9312 2001.01.16 2 N08E60 0060 HSX Total number of sunspots: 55 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.11 191.5 133.2 111.0 (+3.2) 1999.12 169.8 84.6 111.1 (+0.1) 2000.01 158.1 90.1 112.9 (+1.8) 2000.02 174.1 112.9 116.7 (+3.8) 2000.03 208.2 138.5 119.9 (+3.2) 120.8 (+0.9) 2000.04 184.2 125.5 cycle 23 peak candidate 2000.05 184.9 121.6 119.0 (-1.8) 2000.06 179.8 124.9 118.7 (-0.3) 2000.07 202.3 169.1 (120.3 predicted, +1.6) 2000.08 163.0 130.5 (120.8 predicted, +0.5) 2000.09 182.1 109.9 (119.9 predicted, -0.9) 2000.10 167.4 100.1 (118.7 predicted, -1.2) 2000.11 178.8 106.5 (116.8 predicted, -1.9) 2000.12 173.6 104.5 (114.2 predicted, -2.6) 2001.01 172.3 (1) 79.7 (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 noted in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]