Solar Terrestrial Activity Report [Image] Last update March 15, 2001 at 04:40 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 14. Solar wind speed ranged between 370 and 429 km/sec. Solar flare activity was very low. Solar flux was 142.2, the planetary A index was 7 (3-hour K indices: 2233 2121, Boulder K indices: 2233 3222). Region 9373 has lots of small spots spread out over a large area. Magnetically the region is not complex and there is only a minor chance of an M class flare. Region 9374 reemerged with a couple of spots but was spotless again by early evening. Region 9376 was spotless early in the day, then reemerged with a few spots before again decaying into a spotless state by early evening. Region 9380 decayed and was spotless by early evening. Region 9381 was quiet and stable. New region 9382 emerged near the northwest limb but was spotless by early evening. New region 9383 emerged in the southwest quadrant. New region 9384 emerged in the northeast quadrant near the central meridian. Flares and CMEs No flaring of interest was observed on March 14. The background x-ray flux is at the class B3 level. Coronal holes A small, well placed coronal hole in the southern hemisphere will rotate into a geoeffective position on March 14. Only minor, if any, effects on the geomagnetic field are likely on March 17-18. Forecast The geomagnetic field is expected to be quiet to unsettled on March 15-16. 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 9373 2001.03.09 57 S08E07 0190 EAI 9374 2001.03.10 2 S17E03 0000 AXX 9376 2001.03.11 4 S14E34 0010 BXO 9377 2001.03.11 S18W39 plage 9378 2001.03.12 N24W58 plage 9379 2001.03.12 N31E14 plage 9380 2001.03.12 1 S09E40 0010 AXX 9381 2001.03.13 3 S17E24 0020 CRO 9382 2001.03.14 2 N09W74 0010 CSO 9383 2001.03.14 5 S09W44 0020 CSO 9384 2001.03.14 5 N10E02 0010 CSO Total number of sunspots: 79 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) 2001.03 151.9 (1) 55.8 (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. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]