Solar Terrestrial Activity Report [Image] Last update February 22, 2001 at 01:10 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) - Did cycle 23 peak 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 unsettled on February 21. Solar wind speed ranged between 317 and 366 km/sec. Solar flare activity was low. Solar flux was 143.6, the planetary A index was 6 (3-hour K indices: 2112 3221, Boulder K indices: 2122 3211). Regions 9350 and 9353 were quiet and stable. Region 9354 developed slowly and has a magnetic delta configuration. Minor M class flares are possible. Region 9356 reemerged with a single spot. Regions 9357 and 9358 were quiet and stable. Region 9359 developed slowly and could produce C flares and maybe even an isolated minor M class flare. New region 9360 (near the southeast limb) was finally numbered. Flares and CMEs A total of 4 C class event were observed on February 21. Region 9354 produced a C6.2 flare at 14:27 and a C1.2 flare at 20:10 UT. The background x-ray flux is at the class B3 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on February 22-23. 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 Location region numbered no. at Area Classification Comment sunspots midnight 9349 2001.02.10 N30W82 plage 9350 2001.02.11 1 N19W62 0040 HSX 9352 2001.02.15 S21W11 plage 9353 2001.02.16 3 S24W50 0030 DSO 9354 2001.02.16 15 S08W32 0180 DAI beta-gamma-delta 9355 2001.02.18 N20W05 plage 9356 2001.02.18 1 S15W52 0010 AXX 9357 2001.02.18 4 S26W07 0020 CSO 9358 2001.02.18 9 S18E07 0050 DSO 9359 2001.02.20 5 N10E64 0120 DAO 9360 2001.02.21 1 S11E58 0020 HSX Total number of sunspots: 39 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 (119.5 predicted, -0.3) 2000.09 182.1 109.7 (117.9 predicted, -1.6) 2000.10 167.4 100.1 (116.3 predicted, -1.6) 2000.11 178.8 106.5 (114.4 predicted, -1.9) 2000.12 173.6 104.5 (111.8 predicted, -2.6) 2001.01 166.6 95.7 (108.2 predicted, -3.6) 2001.02 149.7 (1) 104.3 (2) 1) Running average based on the daily 20:00 UT 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]