Solar Terrestrial Activity Report [Image] Last update February 23, 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) - 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 22. Solar wind speed ranged between 328 and 372 km/sec. A minor disturbance is in progress. Solar flare activity was low. Solar flux was 145.8, the planetary A index was 7 (3-hour K indices: 0032 1223, Boulder K indices: 1033 2221). Regions 9350 and 9353 were mostly quiet and stable. Region 9354 developed slowly but become magnetically less complex. There is still a possibility of minor M class flaring. Region 9356 was quiet and stable, the region was spotless by early evening. Regions 9357 and 9358 decayed and were quiet. Region 9359 developed further and could produce M class flares. Region 9360 was quiet and stable. New region 9361 emerged in the southeast quadrant near the central meridian, the region appears to be spotless early on Feb.23. Flares and CMEs Only 1 C class event was observed on February 22, region 9353 produced a C1.1 flare at 01:59 UT. The background x-ray flux is at the class B3-B4 level. Coronal holes A coronal hole in the southern hemisphere may be located too far to the south to be geoeffective when it rotates across the central meridian on Feb.23-24. Forecast The geomagnetic field is expected to be quiet to active on February 23 and quiet to unsettled on February 24. 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 9350 2001.02.11 1 N18W76 0050 HSX 9352 2001.02.15 S21W24 plage 9353 2001.02.16 3 S24W64 0010 BXO 9354 2001.02.16 18 S09W45 0200 DAO beta-gamma 9355 2001.02.18 N20W18 plage 9356 2001.02.18 2 S15W66 0020 AXX 9357 2001.02.18 3 S26W20 0010 BXO 9358 2001.02.18 5 S08W05 0010 CSO 9359 2001.02.20 10 N12E52 0190 DAO 9360 2001.02.21 1 S10E45 0030 HSX 9361 2001.02.22 2 S17E07 0000 BXO Total number of sunspots: 45 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) 2001.02 149.6 (1) 109.1 (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]