Solar Terrestrial Activity Report [Image] Last update November 18, 2000 at 05:20 UTC. Minor update posted at 14:33 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update November 1, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update November 1, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update November 1, 2000)] [Historical solar and geomagnetic data charts 1954-2000 (last update October 20, 2000)] Recent development The geomagnetic field was quiet on November 17. Solar wind speed ranged between 321 and 396 km/sec. Solar flare activity was low. Solar flux was 163.3, the planetary A index was 4 (3-hour K indices: 1012 2211, Boulder K indices: 1111 1100). Region 9223 was quiet and stable and rotated over the west limb early today. Region 9227 decayed and is capable of isolated C class flaring. Region 9229 was quiet and stable. Region 9231 remained complex and has M class flaring potential. Region 9232 was quiet and stable. Region 9233 decayed and was quiet. Region 9234 was quiet and stable. Region 9235 developed slowly and could produce minor M class flares. Another region with minor M class flaring potential is rotating into view at the northeast limb. Comment added at 14:33 UTC on November 18: Region 9131 produced an M1.5 flare at 11:00 UTC, it is not yet known if there was a CME associated with this event (LASCO images haven't been updated since late on Nov.17). Region 9135 was the source of a long duration M1.5 event peaking at 13:25 UTC. A moderately strong type II radio sweep was observed with this event and there may well have been produced a geoeffective CME, which could impact Earth on November 21. A weak coronal stream is in progress and could disturb the geomagnetic field slightly for the remainder of the day. Flares and CMEs A total of 7 C class events were recorded on November 17. Region 9231 produced a C2.4 flare at 20:51 and a C2.3 flare at 11:07 UTC. The latter flare was accompanied by a filament eruption to the south and west of the region and the associated CME may have been a partial halo CME. Region 9235 generated a long duration C2.3 event at 18:47 and a C1.6 flare at 22:23 UTC. A part of the southern polar crown filament erupted. This event began at approximately 02:12 UTC and lasted for several hours. A fairly narrow CME was observed off the south pole. The background x-ray flux is at the class B6 level. Coronal holes A small coronal hole in the northern hemisphere was in a geoeffective position on November 15 and could cause a few unsettled to active intervals on November 18. Forecast The geomagnetic field is expected to be quiet to unsettled on November 18-19. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to 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 9223 20001105 1 S15W89 0010 HRX 9227 20001108 3 S10W72 0130 HAX 9228 20001109 N21W81 plage 9229 20001110 4 N07W22 0060 CSO 9231 20001113 34 S24E19 0330 FAI beta-gamma 9232 20001113 7 N24E22 0040 CAO 9233 20001114 1 N12E39 0050 HSX 9234 20001115 1 N20W04 0000 AXX 9235 20001116 9 N14E51 0140 DSO beta-gamma Total number of sunspots: 60 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 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) 2000.03 208.2 138.5 119.8 (+3.2) 2000.04 184.2 125.3 120.7 (+0.9) 2000.05 184.9 120.8 (119.6 predicted, -1.1) 2000.06 179.8 124.9 (120.3 predicted, +0.7) 2000.07 202.3 169.1 (122.4 predicted, +2.1) 2000.08 163.0 130.5 (122.5 predicted, +0.1) 2000.09 182.1 109.9 (121.0 predicted, -1.5) 2000.10 167.4 100.1 (119.8 predicted, -1.2) 2000.11 169.6 (1) 86.1 (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]