Solar Terrestrial Activity Report [Image] Last update March 12, 2001 at 04:00 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 on March 11. Solar wind speed ranged between 357 and 438 km/sec. Solar flare activity was low. Solar flux was 157.8, the planetary A index was 4 (3-hour K indices: 0101 2121, Boulder K indices: 0201 3320). Region 9368 decayed further and was quiet, the region is rotating over the west limb. Region 9370 decayed significantly and was quiet. Region 9372 was quiet and stable, the region is rotating over the west limb. Region 9373 developed further and could produce M class flares. Region 9374 was quiet and stable, no spots are visible early on March 12. Region 9375 was quiet and stable. New region 9376 rotated into view at the southeast limb and could produce C class flares. New region 9377 emerged in the southeast quadrant near the central meridian, no spots are visible early on March 12. Flares and CMEs A total of 6 C class events were recorded on March 11. Region 9376 produced a C5.0 flare at 08:56 UT. The background x-ray flux is at the class B5 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 12-13. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to good. 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 S24W74 9367 2001.03.02 N09W71 plage 9368 2001.03.02 7 N25W73 0210 CAO 9370 2001.03.03 20 N10W51 0150 DAO 9372 2001.03.09 7 S36W76 0110 DAO 9373 2001.03.09 19 S08E48 0230 DAI 9374 2001.03.10 1 S18E38 0000 AXX 9375 2001.03.10 3 S16W58 0010 BXO 9376 2001.03.11 1 S13E72 0030 HRX 9377 2001.03.11 1 S18E01 0000 AXX Total number of sunspots: 59 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) 2001.03 152.7 (1) 41.5 (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]