Solar Terrestrial Activity Report [Image] Last update February 11, 2002 at 03:50 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 unsettled on February 10. Solar wind speed ranged between 418 and 480 km/sec. Solar flare activity was moderate. Solar flux was 216.5 (perhaps influenced by a long duration event which ended at 19:59 UTC), the planetary A index was 8 (3-hour K indices: 3232 2222, Boulder K indices: 2232 3213). Region 9809 decayed slowly and quietly. Region 9810 was quiet and stable. Region 9811 decayed slowly and could be capable of further minor M class flaring. Region 9815 decayed and was spotless by late evening. Regions 9819 and 9820 both decayed and were spotless by early evening. Region 9821 developed further and could produce M class flares. Region 9822 was mostly quiet and stable. Region 9823 developed slowly and quietly. Region 9824 was quiet and stable. Region 9825 is developing slowly and could produce M class flares. New region 9826 emerged in the southeast quadrant and is developing quickly. Flares and CMEs A total of 6 C and 1 M class events were recorded on February 10. Region 9821 produced a C1.9 flare at 01:15 and a C1.8 flare at 23:47 UTC. Region 9811 generated an impulsive M1.6/2F flare at 18:48 UTC. Region 9825 was the source of a C5.5/1F long duration event peaking at 19:28 UTC. The background x-ray flux is at the class C1 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 no. Location region numbered sunspots at Area Classification Comment midnight 9807 2002.01.30 S27W60 plage 9808 2002.01.31 N17W80 plage 9809 2002.01.31 1 S05W63 0040 HSX 9810 2002.02.01 3 N10W41 0120 CSO 9811 2002.02.02 5 S26W20 0100 DSO 9814 2002.02.03 N06W76 plage 9815 2002.02.03 5 N11W24 0040 BXO now spotless 9817 2002.02.05 S06W45 plage 9818 2002.02.05 N06W12 plage 9819 2002.02.05 5 S30E04 0020 BXO now spotless 9820 2002.02.07 1 N14E01 0010 AXX now spotless 9821 2002.02.08 33 S14W11 0280 ESI beta-gamma 9822 2002.02.08 7 N17E40 0070 CSO 9823 2002.02.09 7 S05E09 0030 CSO 9824 2002.02.09 1 N21E54 0130 HSX 9825 2002.02.09 12 N12E57 0480 EKI 9826 2002.02.10 5 S23E39 0020 CAO Total number of sunspots: 85 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) 2002.02 217.6 (1) 84.8 (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]