Solar Terrestrial Activity Report [Image] Last update March 25, 2001 at 05:15 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 24. Solar wind speed ranged between 385 and 444 km/sec. Solar flare activity was moderate. Solar flux was 218.7 (value was somewhat enhanced due to flare activity), the planetary A index was 13 (3-hour K indices: 1343 3332, Boulder K indices: 2443 3331). Region 9387 was quiet and stable. Region 9389 was generally unchanged and could produce occasional minor M class flares. Region 9390 produced a few flares and has M class flare potential. Region 9392 was quiet and stable. Region 9393 has a huge penumbra containing most of its spots. The region is complex and could produce major flares, X flares are possible, as are proton flares. Region 9394 was quiet and stable, as was region 9395. New region 9396 emerged in the southeast quadrant near the central meridian. New region 9397 rotated into view at the southeast limb trailing region 9395. The region could produce M class flares. New region 9398 emerged in the northeast quadrant near the central meridian. New region 9399 emerged in the southeast quadrant. New region 9400 emerged in the northeast quadrant. Flares and CMEs A total of 8 C and 3 M class events were recorded on March 24. Region 9376, at the southwest limb, produced an impulsive M1.2 flare at 01:38 UT. This event was accompanied by a moderate type II sweep. Region 9389 generated a C4.6 flare at 08:14 UT. Region 9393 was the source of a C4.0 flare at 09:08, a C5.8 flare at 14:32 and an M1.1/1F flare at 23:18 UT. Region 9390 produced an M1.7/2N long duration event peaking at 19:55 UT. The background x-ray flux is at the class C2 level. Coronal holes A coronal hole in the northern hemisphere was in 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 were in possibly geoeffective positions on March 22 and 24 and could cause unsettled to active conditions on March 25 and 27. Forecast The geomagnetic field is expected to be quiet to active on March 25 and quiet to unsettled on March 26. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 Location region numbered no. at Area Classification Comment sunspots midnight 9385 2001.03.17 S11W51 plage 9387 2001.03.19 11 N09W07 0150 DSO 9389 2001.03.20 13 S13E26 0150 FAO 9390 2001.03.20 19 N15E19 0100 FAI beta-gamma 9391 2001.03.21 S04W54 plage 9392 2001.03.21 6 N18W58 0040 DSO 9393 2001.03.21 12 N20E54 0820 EKC beta-gamma-delta 9394 2001.03.22 1 N09E48 0010 HSX 9395 2001.03.23 1 S12E63 0150 HSX 9396 2001.03.24 5 S06W04 0020 BXO 9397 2001.03.24 3 S09E76 0290 DSO beta-gamma 9398 2001.03.24 6 N21E02 0010 BXO 9399 2001.03.24 5 S29E03 0010 BXO 9400 2001.03.24 2 N09E35 0010 HRX Total number of sunspots: 84 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) 2001.03 154.9 (1) 94.2 (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]