Solar Terrestrial Activity Report [Image] Last update September 15, 2000 at 01:25 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update September 2, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update September 2, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update September 2, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update August 10, 2000)] Recent development The geomagnetic field was quiet to slightly unsettled on September 14. Solar wind speed ranged between 317 and 378 km/sec. The halo CME observed on September 12 has not yet arrived, solar wind parameters do, however, indicate that the shock front should arrive within a few hours. Solar flare activity was moderate. Solar flux was 150.8, the planetary A index was 6 (3-hour K indices: 1322 2211, Boulder K indices: 2322 2110). Region 9156 developed slowly and was quiet. Region 9158 was quiet and stable, the region could become spotless today or tomorrow. Region 9162 developed slowly early in the day, then decayed slowly. Regions 9163 were quiet and decayed slowly, both regions could soon become spotless. Region 9165 developed quickly and is capable of minor M class flaring. New region 9166 rotated partly into view at the southeast limb, it could be capable of producing further M class flares. Flares and CMEs A total of 8 C and 1 M class events were recorded on September 14. Region 9166 produced a long duration M1.1 event which peaked at 06:27 UTC. Region 9165 generated a C1.6 flare at 10:56 and a C2.1 flare at 14:48 UTC. September 12: A very large full halo coronal mass ejection was observed following a huge filament eruption in the southern hemisphere. Region 9163 was near the center of the eruption which began at 11:00 UTC in LASCO EIT images. This CME could cause a serious disturbance on September 15 after it impacts Earth, minor to severe storming is possible! The background x-ray flux is at the class B6 level. Coronal holes A coronal hole in the southern hemisphere could move into a geoeffective position on September 16-17. Forecast The geomagnetic field is expected to be quiet to severe storm on September 15 and unsettled to active on September 16. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor. 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 9156 20000906 6 S26W53 0060 DAO 9157 20000906 N22W40 plage 9158 20000907 1 N31W22 0000 AXX 9159 20000907 S19W63 plage 9160 20000909 S12W60 plage 9161 20000911 N05E10 plage 9162 20000912 5 S32W63 0080 DAO 9163 20000912 2 S17W36 0010 AXX 9164 20000913 2 S15W27 0010 AXX 9165 20000913 20 N13E14 0140 DAI beta-gamma 9166 20000914 6 S13E71 0070 DSO Total number of sunspots: 39 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1999.07 165.6 113.5 94.3 (+1.2) 1999.08 170.7 93.7 97.5 (+3.2) 1999.09 135.7 71.5 102.3 (+4.8) 1999.10 164.8 116.7 107.8 (+5.5) 1999.11 191.5 133.2 110.9 (+3.1) 1999.12 169.8 84.6 111.0 (+0.1) 2000.01 158.1 90.1 112.8 (+1.8) 2000.02 174.1 112.9 116.6 (+3.8) 2000.03 208.2 138.5 (118.7 predicted, +2.1) 2000.04 184.2 125.3 (119.6 predicted, +0.9) 2000.05 184.9 120.8 (120.4 predicted, +0.8) 2000.06 179.8 124.9 (122.0 predicted, +1.6) 2000.07 202.3 169.1 (124.1 predicted, +2.1) 2000.08 163.0 130.6 2000.09 155.4 (1) 58.2 (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]