Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update February 14, 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 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 quiet to active on February 13. Solar wind speed ranged between 503 and 648 km/sec. A coronal hole based disturbance influenced the geomagnetic field from approximately 04h UTC and for the remainder of the day. Solar flare activity was low. Solar flux was 159.9, the planetary A index was 14 (3-hour Kp indices: 3234 3433, Boulder K indices: 2334 3322). Region 8856 was quiet and stable. Region 8858 decayed further but could still produce occasional C class flares. Region 8862 was quiet and stable. Region 8864 decayed into spotless plage. Region 8867 developed slowly and was quiet. Region 8868 decayed slowly and was quiet. Region 8869 was mostly unchanged and could produce occasional C flares. Region 8870 was quiet and stable, as was region 8872. Region 8871 is developing and could produce C flares. New region 8873 rotated into view at the southeast limb. Flares and CMEs 1 C flare was recorded on February 13, it was a C1.1 flare produced by region 8858 at 05:39 UTC. 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, however, the halo effect may be apparent as a large CME was moving off the northwest limb at almost the same time. February 11: Region 8856 was the source of a C2.3 flare at 12:34 UTC and an associated partial halo coronal mass ejection. This CME could impact Earth on February 14 or 15 and cause a few unsettled to active intervals. The background x-ray flux is at the class B5 level. Coronal holes A coronal hole in the northern hemisphere will rotate into 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.14. Should the partial halo CME observed on February 11 arrive isolated minor storm intervals will be possible on Feb.14 and 15. Low frequency (below 2 MHz) radio wave propagation along east-west paths over high and upper middle latitudes is generally poor to 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 S34W70 plage 8856 20000202 2 S16W61 0040 CSO 8858 20000203 4 N24W50 0020 CSO 8862 20000206 1 S06W19 0150 HSX 8863 20000208 S16E04 plage 8864 20000208 N44W80 plage 8865 20000208 S12W43 plage 8866 20000208 N15W01 plage 8867 20000209 12 S16W19 0030 CRO 8868 20000209 6 S24W21 0050 CSO 8869 20000210 5 S24E36 0040 ESO 8870 20000210 1 N20E38 0080 HSX 8871 20000211 8 S15W35 0030 CSO 8872 20000211 5 S26E53 0070 DAO 8873 20000213 3 S18E66 0010 BXO Total number of sunspots: 47 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 2000.02 167.2 (1) 71.1 (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]