Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update February 2, 2000 at 03:20 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 unsettled on February 1. Solar wind speed ranged between 496 and 583 km/sec under the influence of a (weakening) high speed coronal stream. Solar flare activity was very low. Solar flux was 138.1, the planetary A index was 8 (3-hour Kp indices: 3121 3322, Boulder K indices: 1120 3312). Region 8841 decayed slowly and was quiet. This region and region 8845 will rotate off the visible disk early on February 3. Region 8845 was quiet and stable. Region 8848 was mostly unchanged and could produce occasional C flares. Region 8850 decayed into spotless plage. Region 8851 developed further and was quiet. The region could produce C flares and perhaps even a minor M flare. Region 8852 developed slowly and was quiet, occasional C class flares are possible. New region 8853 rotated into view at the southeast limb. New region 8854 rotated partly into view at the southeast limb. This region appears to be fairly active and may have minor M class flare potential. Flares and CMEs No flaring was observed on February 1. Over the past few days lots of backside coronal mass ejections have been observed in LASCO C2 images. The regions which are the sources of this activity should rotate into view over the next week. The background x-ray flux is at the class B5 level. Coronal holes A trans equatorial coronal hole will likely rotate into a geoeffective position on February 2-4. Forecast The geomagnetic field is expected to be mostly quiet to unsettled February 2-3, a few isolated active intervals are possible. Another coronal hole based disturbance could start late on February 5 and last through February 7. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally 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 8841 20000121 5 S32W74 0080 DSO 8845 20000125 1 S16W74 0010 HRX 8846 20000126 N37W27 plage 8848 20000126 5 S09W01 0080 CSO 8849 20000128 S17W32 plage 8850 20000130 S17W02 plage 8851 20000130 14 N27E16 0130 DAO 8852 20000131 10 N10E00 0030 CRO 8853 20000201 1 S10E64 0000 AXX 8854 20000201 1 S33E81 0020 HSX Total number of sunspots: 37 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 70.9 (105.7 predicted, +6.3) 1999.10 164.8 116.4 1999.11 191.5 132.7 1999.12 169.8 86.4 2000.01 158.1 140.9 (2) 2000.02 138.1 (1) 3.7 (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]