Solar Terrestrial Activity Report [Image] Last update February 12, 2002 at 05:25 UTC. [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, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update February 2, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update February 2, 2002)] [Historical solar and geomagnetic data charts 1954-2001 (last update January 12, 2002)] Recent development The geomagnetic field was quiet to active on February 11. Solar wind speed ranged between 402 and 613 km/sec. A fairly benign coronal stream began influencing the field after 06h UTC. Solar flare activity was low. Solar flux was 201.7, the planetary A index was 13 (3-hour K indices: 2234 3333, Boulder K indices: 2223 3423). Region 9809 was quiet and stable and is about to rotate over the southwest limb. Region 9810 was quiet and stable, as was region 9811. Region 9819 was spotless in all available images, SEC/NOAA recorded 2 spots. Region 9821 developed slowly and could produce M class flares. Region 9822 decayed slowly and was mostly quiet. Region 9823 developed slowly and quietly. Region 9824 was quiet and stable. Region 9825 developed further and could produce M class flares. Region 9826 was quiet and stable. New region 9827 emerged in the southwest quadrant. New region 9828 emerged in the southeast quadrant. Flares and CMEs A total of 8 C class events were recorded on February 11. Region 9821 produced a C1.6 flare at 00:49, a C2.1 flare at 03:33 and a C1.2 flare at 14:02 UTC. Region 982 generated a C2.0 flare at 09:29 UTC, while region 9825 was the source of a C1.5 flare at 21:44 and a C2.3 flare at 23:00 UTC. The background x-ray flux is at the class B9 level. Coronal holes What could be a small coronal hole in the southern hemisphere will rotate into a geoeffective position on February 12. Forecast The geomagnetic field is expected to be quiet to unsettled on February 11-13. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor and slowly improving. 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 9807 2002.01.30 S27W73 plage 9809 2002.01.31 1 S06W76 0040 HSX 9810 2002.02.01 3 N10W54 0100 CSO 9811 2002.02.02 8 S26W32 0070 DAO 9814 2002.02.03 N06W89 plage 9815 2002.02.03 N11W37 plage 9817 2002.02.05 S06W58 plage 9818 2002.02.05 N06W25 plage 9819 2002.02.05 2 S30W06 0020 DSO actually spotless 9820 2002.02.07 N14W12 plage 9821 2002.02.08 32 S13W25 0310 EAI beta-gamma 9822 2002.02.08 7 N18E26 0040 CAO 9823 2002.02.09 7 S04W05 0050 DAO 9824 2002.02.09 1 N21E41 0130 HAX 9825 2002.02.09 16 N12E43 0380 EKI 9826 2002.02.10 7 S23E25 0040 DSO 9827 2002.02.11 1 S25W43 0010 AXX 9828 2002.02.11 1 S15E50 0020 HSX Total number of sunspots: 86 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 2000.04 184.2 125.5 120.8 cycle 23 sunspot max. 2000.07 202.3 170.1 119.8 2000.12 173.6 104.4 112.0 (-0.7) 2001.01 166.6 95.6 108.7 (-3.3) 2001.02 146.6 80.6 104.1 (-4.6) 2001.03 177.7 113.5 104.8 (+0.7) 2001.04 177.7 107.7 107.6 (+2.8) 2001.05 147.1 96.6 108.7 (+1.1) 2001.06 173.0 134.0 109.8 (+1.1) 2001.07 131.3 82.2 111.7 (+1.9) 2001.08 162.9 106.8 (113.5 predicted, +1.8) 2001.09 233.2 150.7 (113.3 predicted, -0.2) 2001.10 207.6 125.6 (111.0 predicted, -2.3) 2001.11 210.6 106.5 (109.6 predicted, -1.4) 2001.12 235.1 131.8 (106.2 predicted, -3.4) 2002.01 226.6 113.9 (102.6 predicted, -3.6) 2002.02 216.1 (1) 92.1 (2) (101.2 predicted, -1.4) 1) Running average based on the daily 20:00 UT solar flux value at 2800 MHz. 2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official international sunspot number 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]