Solar Terrestrial Activity Report [Image] Last update March 16, 2001 at 04:30 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 15. Solar wind speed ranged between 292 and 391 km/sec. Solar flare activity was low. Solar flux was 136.1, the planetary A index was 3 (3-hour K indices: 0021 1121, Boulder K indices: 1010 2211). Region 9373 developed early in the day, however, the region appears to be decaying now. Early on March 16 the region has lost some of its areal coverage and quite a few spots. Region 9376 was spotless early in the day, then reemerged with several spots. The region could become spotless again later today. Region 9381 was quiet and stable, no spots are visible early on March 16. Region 9383 developed slowly and was mostly quiet, the region was decaying late in the day. Region 9384 developed slowly and may be capable of further C class flare production. Flares and CMEs A total of 3 C class events were recorded on March 15. Region 9373 produced a C1.5 flare at 21:20 and a C2.1 flare at 22:17 UT. Region 9384 generated a C1.9 flare at 21:59 UT. A filament eruption occurred near region 9384 and was in progress by 21:13 UT according to LASCO EIT images. The eruption is likely to have produced a geoeffective CME. The background x-ray flux is at the class B4 level. Coronal holes A small, well placed coronal hole in the southern hemisphere was in 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 16-17. A CME based disturbance could start on March 18 and cause the field to become unsettled to active. 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 9373 2001.03.09 53 S07W06 0240 FSI beta-gamma 9374 2001.03.10 S17W10 plage 9376 2001.03.11 7 S14E21 0010 BXO 9377 2001.03.11 S18W52 plage 9378 2001.03.12 N24W71 plage 9379 2001.03.12 N31E01 plage 9380 2001.03.12 S09E27 plage 9381 2001.03.13 2 S17E09 0020 AXX 9382 2001.03.14 N09W87 plage 9383 2001.03.14 6 S10W58 0080 DAO 9384 2001.03.14 8 N10W11 0040 DSO Total number of sunspots: 76 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) 2001.03 150.8 (1) 59.9 (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]