Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update January 17, 2000 at 03:00 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update January 1, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update January 1, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update January 1, 2000)] [Historical solar and geomagnetic data charts 1954-1999] [Experimental solar data chart January 1998-September 1999] Recent development The geomagnetic field was quiet to slightly unsettled on January 16. Solar wind speed ranged between 364 and 423 km/sec. Solar flare activity was low. Solar flux was 207.7, the planetary A index was 6 (3-hour Kp indices: 2101 2223, Boulder K indices: 2101 2221). Region 8821 decayed slowly and was quiet. Region 8824 decayed slowly and was generally quiet. Isolated M flares are possible. Region 8825 reemerged with a couple of spots. Region 8826 was quiet and stable and will rotate over the west limb today. Region 8827 is fairly bright and has a chance of generating a minor M flare while rotating over the west limb today. Region 8828 did not change significantly and was quiet. Region 8829 decayed slowly and was quiet. The region could generate an isolated M flare. Region 8831 developed further and has minor M class flaring potential. Region 8832 decayed and was quiet. Region 8833 was quiet and stable. Region 8834 changed little and will be rotating off the visible disk early on January 18. Region 8835 was quiet and stable. New region 8836 emerged near the southeast limb. Flares and CMEs 2 C flares were recorded on January 16. An optically uncorrelated C2.9 flare was observed at 01:49 UTC. Region 8829 produced a C1.9 flare at 19:45 UTC. A fairly large filament eruption was observed in LASCO EIT movies. The event was first observed at 03:12 UTC and occurred 15-25 degrees east of the central meridian and spanned 15-20 degrees on either side of the solar equator. There may have been a weak CME in LASCO C2 images. The CME could be geoeffective. The background x-ray flux is at the class B9 level. Coronal holes A small coronal hole in the southern hemisphere will move into a geoeffective position on January 17-18 and could cause a slight increase in geomagnetic activity on January 20 or 21. Forecast The geomagnetic field is expected to be mostly quiet on January 17-18. On January 19-20 there is a possibility of an impact from CME produced by a filament eruption on January 16. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally 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 8820 20000106 S15W59 plage 8821 20000106 4 N27W48 0080 CSO 8823 20000108 S32W40 plage 8824 20000109 53 S13W17 0380 EAC beta-gamma 8825 20000110 2 N11W16 0000 AXX 8826 20000111 2 N18W84 0000 AXX 8827 20000111 6 S11W84 0080 CAO 8828 20000111 18 S22W09 0100 DAO 8829 20000111 12 N16E10 0110 ESO 8830 20000112 S10W42 plage 8831 20000112 23 S17E27 0160 DAO 8832 20000113 5 S16W39 0010 BXO 8833 20000113 1 N19E39 0180 HSX 8834 20000115 2 S16W73 0030 CRO 8835 20000115 2 N09E42 0010 BXO 8836 20000116 2 S12E49 0010 BXO Total number of sunspots: 132 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 1998.12 150.1 81.9 77.9 (+4.9) 1999.01 140.6 62.0 82.6 (+4.7) 1999.02 141.9 66.3 84.6 (+2.0) 1999.03 126.3 68.8 83.8 (-0.8) 1999.04 117.2 63.7 85.4 (+1.6) 1999.05 148.4 106.4 90.4 (+5.0) 1999.06 169.8 137.7 93.0 (+2.6) 1999.07 165.6 113.5 (94.8 predicted, +1.8) 1999.08 170.7 93.7 (99.4 predicted, +4.6) 1999.09 135.7 70.6 (105.7 predicted, +6.3) 1999.10 164.8 116.4 1999.11 191.5 132.7 1999.12 169.8 86.4 2000.01 164.6 (1) 75.8 (2) 1) Running average based on the daily 20:00 UTC solar flux measurement at 2800 MHz by DRAO. 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]