Solar Terrestrial Activity Report [Planetary A Index, Solar Flux and SEC sunspot number] Last update January 4, 2000 at 01:30 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 active on January 3. Solar wind speed ranged between 554 and 727 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 133.1, the planetary A index was 13 (3-hour Kp indices: 4333 2232, Boulder K indices: 3333 3222). Region 8810 decayed slowly and was quiet. Region 8813 developed slowly and is likely to produce occasional C flares. Region 8814 was quiet and stable. Region 8815 developed slowly and could produce further C flares. A couple of active regions are approaching the east limb, one each at the southeast and northeast limbs. Flares and CMEs Only 2 C flares were recorded on January 3. Region 8815 was the source of a C1.3 flare at 04:26 UTC while an optically uncorrelated C1.2 flare was observed at 19:16 UTC. The background x-ray flux is at the class B3 level. Coronal holes A large trans equatorial coronal hole was in a geoeffective position on December 28 - January 1. Forecast The geomagnetic field is expected to be quiet to active on January 4. Quiet to unsettled is likely on January 5-6. 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 8809 19991224 N24W59 plage 8810 19991224 4 N38W42 0160 ESO 8812 19991229 S27W86 plage 8813 19991229 14 S16W07 0130 DAO 8814 19991229 4 N10E08 0140 CAO 8815 19991231 15 N08E22 0050 CAO 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 70.6 (105.7 predicted, +6.3) 1999.10 164.8 116.4 1999.11 191.5 132.7 1999.12 169.8 86.4 2000.01 132.0 (1) 6.9 (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]