Solar Terrestrial Activity Report [Image] Last update March 13, 2001 at 04:45 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) - Cycle 23 sunspot maximum was in April 2000] [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 unsettled on March 12. Solar wind speed ranged between 338 and 412 km/sec. A solar wind disturbance arrived at SOHO at approximately 05:10 UT, the disturbance was probably related to the late arrival of the halo CME observed on March 8. Solar flare activity was low. Solar flux was 157.6, the planetary A index was 10 (3-hour K indices: 1023 3333, Boulder K indices: 0023 3423). Region 9368 rotated out of view by the evening. Region 9370 decayed further and had only a few spots left late in the day. Region 9372 rotated out of view by the end of the day. Region 9373 stabilized but is capable of minor M class flare production. Region 9374 was spotless all day in all available images. Region 9375 decayed and was spotless by the end of the day. Region 9376 was mostly unchanged and unstable. Further C class flaring is likely with a possibility of a minor M class flare. Region 9377 was spotless all day in all available images. New region 9378 emerged in the northwest quadrant, the region appears to be decaying and could become spotless today. New region 9379 emerged quickly in the northeast quadrant with several spots, then decayed and lost all but one spot. New region 9380 rotated into view at the southeast limb. Flares and CMEs A total of 6 C class events were recorded on March 12. Region 9373 produced a C2.0 flare at 00:10 and a C1.1 flare at 02:26 UT. Region 9376 generated a C3.1 flare at 02:42, a long duration C4.7 event peaking at 17:37 and a long duration C3.2 event peaking at 18:54 UT. The background x-ray flux is at the class B4 level. Coronal holes No obvious coronal holes are currently approaching geoeffective positions. Forecast The geomagnetic field is expected to be quiet to unsettled on March 13-14. 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 9366 2001.03.02 S24W87 9367 2001.03.02 N09W84 plage 9368 2001.03.02 2 N24W84 0080 CAO 9370 2001.03.03 13 N10W65 0130 EAO 9372 2001.03.09 4 S35W88 0040 CSO 9373 2001.03.09 32 S08E34 0320 EAI 9374 2001.03.10 1 S18E28 0000 AXX actually spotless 9375 2001.03.10 1 S16W71 0020 HSX 9376 2001.03.11 4 S15E57 0040 CRO 9377 2001.03.11 1 S18W13 0000 AXX actually spotless 9378 2001.03.12 4 N24W32 0020 BXO 9379 2001.03.12 1 N31E39 0020 HSX 9380 2001.03.12 1 S09E66 0010 HSX Total number of sunspots: 64 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 peak 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) 2001.03 153.1 (1) 47.2 (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. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]