Solar Terrestrial Activity Report [Image] Last update March 11, 2001 at 05:30 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 to unsettled on March 10. Solar wind speed ranged between 390 and 466 km/sec. Solar flare activity was high. Solar flux was 160.1, the planetary A index was 5 (3-hour K indices: 1211 2231, Boulder K indices: 0312 1221). Region 9368 produced a major flare and decayed quickly afterwards. Early on March 11 the region has lost most of its spots. Region 9370 developed new spots but lost some of its areal coverage. The region was quiet and could be in slow decay. Region 9372 developed early in the day, later on it began to decay. Region 9373 is developing at a moderate pace and could produce minor M class flares. New region 9374 in the southeast quadrant was finally numbered, the region is decaying and could become spotless by the end of the day. New region 9375 emerged in the southwest quadrant, it is already decaying and could soon become spotless. Flares and CMEs A total of 13 C and 1 M class events were recorded on March 10. Region 9372 generated a C3.7 flare at 00:10, a C1.6 flare at 06:55, a C2.7 flare at 07:15, a C1.6 flare at 07:37 and a C3.1 flare at 09:52 UT. Region 9368 produced an impulsive major M6.7/1B flare at 04:05 UT, a weak type II sweep was associated with the event. Region 9373 was the source of a C1.5 flare at 16:00 and a C1.0 flare at 22:55 UT. March 8: Region 9368 generated an impulsive major M5.7/1B flare at 11:18 UT. A moderate type II sweep was associated with the flare. A weak full halo CME was observed in LASCO images with most of the mass observed over the northwest limb. The background x-ray flux is at the class B7 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 11-13 with a possibility of isolated active periods on March 11 due to weak CME effects. 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 S24W61 9367 2001.03.02 N09W58 plage 9368 2001.03.02 16 N24W59 0340 CHO 9370 2001.03.03 31 N10W38 0150 EAI 9372 2001.03.09 10 S36W64 0100 DAO 9373 2001.03.09 9 S07E61 0190 DAO 9374 2001.03.10 1 S19E50 0010 HRX 9375 2001.03.10 4 S16W46 0030 DSO Total number of sunspots: 71 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) 2001.03 152.1 (1) 37.1 (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]