Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update February 15, 2000 at 01:45 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update February 3, 2000)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update February 3, 2000)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update February 3, 2000)] [Historical solar and geomagnetic data charts 1954-1999] [Experimental solar data chart January 1998-September 1999] Recent development The geomagnetic field was unsettled to major storm on February 14. Solar wind speed ranged between 539 and 709 km/sec. A coronal stream was replaced by the effects from the arrival of a CME at 07h UTC. Solar wind speeds quickly increased from 550 to 700 km/sec. The CME was likely the partial halo CME observed on February 11 but could even have been the halo CME observed on February 12. Solar flare activity was very low. Solar flux was 158.7, the planetary A index was 29 (3-hour Kp indices: 3445 6433, Boulder K indices: 3444 5323). Region 8856 was quiet and stable, the region is rotating over the west limb. Region 8858 decayed further and was quiet. Region 8862 was quiet and stable. Region 8867 did not change significantly and was quiet. Region 8868 decayed further and was quiet. Region 8869 was quiet and stable, as was region 8870. Region 8871 developed slowly and could produce C flares. Region 8872 was mostly unchanged and quiet. Region 8873 was quiet and stable. New region 8874 emerged near region 8873 at the southeast limb. Flares and CMEs No flaring of significance was observed on February 14. February 12: Region 8858 was the source of a long duration M1.7/1N event peaking at 04:10 UTC. A weak type II sweep and a strong type IV sweep were associated with the LDE. A full halo CME was observed in LASCO C2 images. A terrestrial impact would be likely on February 15. The background x-ray flux is at the class B3-B4 level. Coronal holes A coronal hole in the northern hemisphere was in a possibly geoeffective position on February 13-14 and could cause unsettled to active intervals on Feb.16-17. The coronal hole may, however, be located just too far to the north to be geoeffective. Forecast The geomagnetic field is expected to be quiet to active on Feb.15. In case of an impact from the CME observed on February 12, active to major storm intervals will be possible. Unsettled to active is possible on Feb.16-17 due to a coronal stream. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally very 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 8854 20000201 S34W83 plage 8856 20000202 3 S16W75 0030 CSO 8858 20000203 2 N25W61 0020 HRX 8862 20000206 1 S06W33 0140 HSX 8863 20000208 S16W09 plage 8865 20000208 S12W56 plage 8866 20000208 N15W14 plage 8867 20000209 10 S16W33 0040 CAO 8868 20000209 4 S24W35 0020 CSO 8869 20000210 5 S24E22 0030 CSO 8870 20000210 1 N19E25 0060 HSX 8871 20000211 11 S15W48 0060 DAO 8872 20000211 5 S27E40 0050 DAO 8873 20000213 3 S18E54 0010 BXO 8874 20000214 3 S08E54 0010 BXO Total number of sunspots: 48 Monthly solar data Month Average solar International sunspot Smoothed sunspot flux number number 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 94.4 (+1.4) 1999.08 170.7 93.7 (97.4 predicted, +3.0) 1999.09 135.7 70.9 (102.4 predicted, +5.0) 1999.10 164.8 116.4 (107.5 predicted, +5.1) 1999.11 191.5 132.7 1999.12 169.8 86.4 2000.01 158.1 90.2 2000.02 166.6 (1) 76.4 (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]