Solar Terrestrial Activity Report [Image] Last update March 22, 2001 at 04:50 UT. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update March 1, 2001)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update March 1, 2001)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update March 1, 2001)] [Historical solar and geomagnetic data charts 1954-2000 (last update January 18, 2001)] Recent development The geomagnetic field was quiet to active on March 21. Solar wind speed ranged between 301 and 406 km/sec, slowly decreasing most of the day. Solar flare activity was moderate. Solar flux was 159.4, the planetary A index was 10 (3-hour K indices: 4331 2222, Boulder K indices: 3331 1111). Region 9373 continued to produce flares and will rotate off the visible disk today. Region 9380 reemerged with a couple of spots, the region is spotless again early on March 22. Region 9384 decayed and was spotless by early evening. Region 9387 was quiet and stable. Region 9388 was quiet and in slow decay. Region 9389 rotated fully into view and may be capable of occasional minor M class flaring. Region 9390 rotated fully into view and has M class flare potential. New region 9391 emerged in the southwest quadrant near the center of the solar disk, the region is spotless early on March 22. New region 9392 emerged quickly in the northwest quadrant. A fairly active region appears to be trailing region 9390 at the northeast limb and could begin to rotate into view today. Flares and CMEs A total of 7 C and 1 M class events were recorded on March 21. Region 9373 produced an M1.8 flare at 02:37 and a C9.8 flare at 11:27 UT. Region 9389 generated a C5.6 flare at 07:24 UT. March 19: A filament eruption began at approximately 04:12 UT in the southern hemisphere and near the center of the solar disk. A weak full halo CME was observed later on in LASCO C3 images and will likely arrive at Earth on March 22. The background x-ray flux is at the class C1 level. Coronal holes A small, well placed coronal hole in the northern hemisphere was in a geoeffective position on March 19-20. Geomagnetic effects beyond a few unsettled to active intervals on March 22-23 are unlikely. Another coronal hole in the northern hemisphere will rotate into a geoeffective position on March 22 and could cause unsettled to active conditions on March 25. Fingers of a fairly large southern hemisphere coronal hole could rotate into geoeffective positions on March 22 and 24 and cause unsettled to active conditions on March 25 and 27. Forecast The geomagnetic field is expected to be quiet to active on March 22-23. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very 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 9373 2001.03.09 10 S06W81 0180 EAO beta-gamma 9374 2001.03.10 S17W88 plage 9376 2001.03.11 S13W56 plage 9379 2001.03.12 N31W77 plage 9380 2001.03.12 2 S08W51 0010 HSX 9381 2001.03.13 S17W69 plage 9384 2001.03.14 1 N18W81 0000 AXX 9385 2001.03.17 S11W12 plage 9386 2001.03.18 N04W53 plage 9387 2001.03.19 13 N09E34 0110 DAO 9388 2001.03.20 2 N14W62 0010 HSX 9389 2001.03.20 3 S13E66 0110 EAO 9390 2001.03.20 9 N14E60 0280 EAO 9391 2001.03.21 2 S04W15 0010 HSX 9392 2001.03.21 4 N20W17 0070 DAO Total number of sunspots: 46 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 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) 2000.04 184.2 125.5 120.8 (+0.9) cycle 23 sunspot max. 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) 2000.08 163.0 130.5 118.6 (-1.2) 2000.09 182.1 109.7 (115.4 predicted, -3.2) 2000.10 167.4 100.1 (113.0 predicted, -2.4) 2000.11 178.8 106.5 (111.0 predicted, -2.0) 2000.12 173.6 104.5 (108.5 predicted, -2.5) 2001.01 166.6 95.7 (104.7 predicted, -3.8) 2001.02 146.6 80.1 (100.3 predicted, -4.4) 2001.03 149.3 (1) 78.8 (2) (96.8 predicted, -3.5) 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. ------------------------------------------------------------------------ Do you know about the survey which will be held this Summer among the listeners of WWV and WWVH? There is information about this survey at 16 minutes past the hour on WWV and at 47 minutes past the hour on WWVH. If you want to participate send an email with your name and address. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]