Solar Terrestrial Activity Report [Image] Last update February 14, 2001 at 04:25 UT. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update February 2, 2001) - Cycle 23 peaked in April 2000?] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update February 2, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update February 2, 2001)] [Historical solar and geomagnetic data charts 1954-2000 (last update January 18, 2001)] Recent development The geomagnetic field was quiet to active on February 13. Solar wind speed ranged between 439 and 647 km/sec. Having peaked early in the day, solar wind speed gradually decreased until approximately 14 UT. Then a fairly quick increase in speed was observed and this may have been the arrival of the halo CME observed on February 11. Solar flare activity was low. Solar flux was 141.3, the planetary A index was 19 (3-hour K indices: 2443 3444, Boulder K indices: 2433 3543). Region 9338 decayed further and was quiet. Region 9339 decayed slowly and was quiet. Region 9342 reemerged with several spots. Region 9345 was quiet and is spotless. Region 9347 was quiet and stable, as were regions 9349 and 9350. Region 9348 reemerged from its spotless state and developed quickly. Further C class flares are possible. Flares and CMEs Only 1 C class event was recorded on February 13. Region 9348 produced a C1.1 flare at 16:33 UT. The background x-ray flux is at the class B2 level. Coronal holes A poorly defined coronal hole in the northern hemisphere was in a geoeffective position on February 12-13. A weak coronal stream could arrive at Earth on February 15. Forecast The geomagnetic field is expected to be quiet to active on February 14. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 9334 2001.02.01 N13W78 plage 9335 2001.02.03 N11W68 plage 9337 2001.02.03 S28W53 plage 9338 2001.02.04 6 S20W54 0150 DSO 9339 2001.02.04 2 S09W52 0080 HSX 9341 2001.02.06 S09W69 plage 9342 2001.02.06 7 S27W31 0020 CAO 9343 2001.02.07 N03W70 plage 9344 2001.02.08 N30W53 plage 9345 2001.02.08 2 S20W45 0000 AXX 9347 2001.02.09 3 N04E12 0030 DSO 9348 2001.02.10 10 N15W33 0040 DAO 9349 2001.02.10 1 N28E21 0030 HSX 9350 2001.02.11 2 N18E43 0060 HSX Total number of sunspots: 33 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) 2000.02 174.1 112.9 116.8 (+3.9) 2000.03 208.2 138.5 119.9 (+3.1) 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) 2000.07 202.3 170.1 119.8 (+1.1) 2000.08 163.0 130.5 (119.7 predicted, -0.1) 2000.09 182.1 109.7 (118.4 predicted, -1.3) 2000.10 167.4 100.1 (116.7 predicted, -1.7) 2000.11 178.8 106.5 (114.8 predicted, -1.9) 2000.12 173.6 104.5 (112.2 predicted, -2.6) 2001.01 166.6 95.7 (108.7 predicted, -3.5) 2001.02 158.1 (1) 69.7 (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]