Solar Terrestrial Activity Report [Image] Last update March 22, 2000 at 02:40 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update March 2, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update March 2, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update March 2, 2000)] [Historical solar and geomagnetic data charts 1954-1999] Recent development The geomagnetic field was quiet to unsettled on March 21. Solar wind speed ranged between 335 and 432 km/sec. A coronal stream based disturbance seems to be in progress as I write this. Solar flare activity was moderate. Solar flux was 230.5, the planetary A index was 6 (3-hour K indices: 1011 3222, Boulder K indices: 0000 0321). Region 8910 lost many spots but is still a complex region capable of producing a major flare. Region 8913 lost spots as well and could produce a minor M class flare. Region 8915 was quiet and stable. Region 8916 was mostly unchanged and could generate minor M class flares. Region 8917 did not display any major changes and is capable of producing a minor M flare. Region 8918 developed further and could produce another M class flare. Region 8919 reemerged with a single spot. Region 8920 was quiet and stable. Region 8921 was mostly unchanged and could produce occasional M flares. New region 8922 emerged near the northeast limb. An active region is approaching the northeast limb and appears to be capable of M class flaring. Flares and CMEs A total of 4 C flares and 1 M flare were recorded on March 21. Region 8910 produced a C5.2 flare at 02:43 and a C7.1 flare at 07:24 UTC. Region 8918 was the source of an M1.0 flare at 14:24 UTC. The flare was accompanied by a weak type II sweep and a fairly fast CME. The region just behind the northeast limb generated a C8.8 flare at 21:41 UTC. Region 8910 produced an M1.9 flare at 01:18 on March 22. The background x-ray flux is at the class C2 level. Coronal holes The large coronal hole that has been around for several months has split into three smaller coronal holes. One is in the northern hemisphere and was in a geoeffective position on March 19, another (fairly small and closing because of development in region 8913) is in the southern hemisphere and was in a geoeffective position on March 20. The third, and largest remaining part, is trans equatorial and should rotate into a geoeffective position on March 21-22. Forecast The geomagnetic field is expected to be quiet to active on March 22-25 due to coronal streams. 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 8908 20000309 S23W83 plage 8909 20000311 S28W54 plage 8910 20000312 26 N12W49 0610 EKC beta-delta 8913 20000314 21 S16W24 0260 EAO 8914 20000316 N16W60 plage 8915 20000316 4 N22E13 0170 CAO 8916 20000317 10 N13E27 0300 DAO 8917 20000318 10 N19W22 0180 DAO 8918 20000319 9 N32W41 0210 EAO 8919 20000319 1 S21E30 0000 AXX 8920 20000320 1 N24E40 0000 AXX 8921 20000320 6 S16E60 0080 CAO 8922 20000321 2 N14E57 0010 AXX Total number of sunspots: 91 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.02 141.9 66.1 84.6 (+2.0) 1999.03 126.3 69.1 83.8 (-0.8) 1999.04 117.2 63.9 85.4 (+1.6) 1999.05 148.4 106.3 90.4 (+5.0) 1999.06 169.8 137.7 93.0 (+2.6) 1999.07 165.6 113.5 94.4 (+1.4) 1999.08 170.7 93.7 97.5 (+3.1) 1999.09 135.7 71.5 (102.6 predicted, +5.1) 1999.10 164.8 116.4 (107.7 predicted, +5.1) 1999.11 191.5 132.7 (110.2 predicted, +2.5) 1999.12 169.8 86.4 2000.01 158.1 90.2 2000.02 174.1 112.3 2000.03 205.4 (1) 127.0 (2) 1) Running average based on the daily 20:00 UTC solar flux value at 2800 MHz.. 2) Unofficial, accumulated value. The official value 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 in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News] [StudyWeb]