Solar Terrestrial Activity Report [Image] Last update March 30, 2001 at 03:10 UT. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update 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 minor storm on March 29. Solar wind speed ranged between 451 and 593 km/sec. Solar flare activity was high. Solar flux was 261.7, the planetary A index was 22 (3-hour K indices: 4453 3423, Boulder K indices: 5443 3432). Region 9387 was quiet and stable, the region is rotating off the visible disk. Regions 9389 and 9390 were quiet and stable. Region 9393 is a very large and complex region capable of producing further X class flares. Another X class flare would likely be a large proton event as well. Region 9394 decayed and was spotless by the end of the day. Region 9395 decayed slowly and was quiet. Region 9396 decayed and was quiet. Region 9397 decayed slightly and is capable of producing minor M class flares. Regions 9399 and 9400 decayed and were spotless by early evening. Region 9401 developed slowly and could produce minor M class flares. Region 9402 is actually spotless as the spot assigned to this region belongs to region 9390. Region 9403 decayed slowly and was quiet. Region 9404 was quiet and stable. Region 9405 decayed and was spotless by the end of the day. Regions 9406 and 9407 were quiet and stable. Region 9408 developed further and could produce a minor M class flare. Mysteriously, for the second day in a row, SEC/NOAA failed to number a region at a high latitude in the southeast quadrant, this region has been spotted since it rotated into view. Flares and CMEs A total of 6 C, 7 M and 1 X class events were recorded on March 29. Region 9393 produced an M2.1/1N flare at 02:56, a C5.5 flare at 05:14, an X1.7/1F flare at 10:15 (accompanied by a strong type IV sweep and a very fast full halo CME. This CME will likely impact the magnetosphere sometime between 16h today and 04h on March 31 and cause severe geomagnetic storming. A fairly weak proton event is in progress following this X flare, the above 10 MeV proton flux has so far peaked at the 29 pfu level), an M2.1 flare at 11:35, a C7.6 flare at 12:39, an M1.6 flare at 14:18, an M1.3 flare at 14:34, an M1.5 flare at 14:58, an M1.2 flare at 15:25, a C5.4 flare at 17:37, a C6.9 flare at 20:17 and an M1.2 flare at 21:01 UT. Region 9397 generated a C6.3 flare at 16:35 UT. March 28: Two full halo CME were observed during the day, the halos were similar in appearance, brightness and velocity and may have had the same source. The first halo was observed in LASCO C2 images beginning at 01:27 UT while the second was first observed at 12:50 UT. LASCO EIT images unfortunately do not point conclusively to a source for either of the CMEs. The long duration M4.3 event in region 9393 may have contributed to the latter halo, however, there is a possibility both events may have a backside origin. If both or one of the CMEs had a frontside origin Earth will receive an impact sometime between noon on March 30 and noon on March 31. The background x-ray flux is at the class C3 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to severe storm on March 30 and active to very severe storm on March 31. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor to 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 Location region numbered no. at Area Classification Comment sunspots midnight 9387 2001.03.19 1 N08W80 0110 HSX 9389 2001.03.20 12 S12W50 0050 DSO 9390 2001.03.20 3 N14W50 0050 CSO 9393 2001.03.21 51 N17W18 2440 FKC beta-gamma-delta 9394 2001.03.22 1 N08W20 0000 AXX 9395 2001.03.23 1 S13W06 0050 HAX 9396 2001.03.24 7 S06W72 0240 DAO 9397 2001.03.24 13 S09E06 0220 EAO beta-gamma 9398 2001.03.24 N21W65 plage 9399 2001.03.24 1 S31W60 0000 AXX 9400 2001.03.24 1 N10W44 0000 AXX 9401 2001.03.25 18 N21E03 0210 DAI region is 9402 2001.03.25 1 N18W47 0010 HRX spotless, spot belongs to region 9390 9403 2001.03.26 3 S13E20 0010 BXO 9404 2001.03.27 1 S05E36 0070 HAX 9405 2001.03.28 3 S13W34 0010 AXX 9406 2001.03.28 1 N26E52 0160 HSX 9407 2001.03.28 2 N13E54 0110 CSO 9408 2001.03.28 15 S10E24 0200 EAI Total number of sunspots: 135 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) 2001.03 172.7 (1) 145.0 (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]