Last major update issued on September 9, 2007 at 02:25 UTC.
geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-23 (last update July 23, 2007)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update July 23, 2007)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update July 23, 2007)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports (last update July 1, 2007)]
The geomagnetic field was quiet on September 8. Solar wind speed ranged between 408 and 469 km/s (average speed was 454 km/s, decreasing 33 km/s from the previous day).
Solar flux measured at 20h UTC on 2.8 GHz was 66.6. The planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.0). Three hour interval K indices: 22221221 (planetary), 12331221 (Boulder).
The background x-ray flux is below the class A1 level.
At midnight the visible solar disk was spotless. The solar flare activity level was very low. No C class events were recorded during the day.
September 6-8: No obvious fully or partly Earth directed CMEs were observed in LASCO imagery.
history (since late October 2002)
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A recurrent coronal hole (CH290) in the southern hemisphere could rotate into an Earth facing position on September 10.
Processed SOHO/EIT 195 image at 00:00 UTC on September 9. The darkest areas on the solar disk are likely coronal holes.
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is fair. Propagation on long distance northeast-southwest paths is poor.
Monitoring remarks from a location near N58E06: September 9: Strong signals were noted from a number of TA stations, in particular stations from Cuba enjoyed good propagation. Reception from North America was much improved. There were a few surprises as 1600 KGYM and 1650 KCNZ both had excellent signals for quite a while.
The geomagnetic field is expected to be quiet on September 9-13. Some unsettled and active intervals are possible on September 14 due to effects from CH290.
|Coronal holes (1)||Coronal mass ejections (2)||M and X class flares (3)|
1) Effects from a coronal hole could reach Earth
within the next 5 days. When the high speed stream has arrived the
color changes to green.
2) Effects from a CME are likely to be observed at 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.
Compare to the previous day's image.
|Active region||Date numbered||SEC
|Location at midnight||Area||Classification||Comment|
|Total spot count:||0||0|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2007.03||72.2||4.8||(11.1 predicted, -0.5)|
|2007.04||72.4||3.7||(10.7 predicted, -0.4)|
|2007.05||74.4||11.7||(10.2 predicted, -0.5)|
|2007.06||73.7||12.0||(10.0 predicted, -0.2)|
|2007.07||71.6||10.0||(10.0 predicted, +0.0)|
|2007.08||69.1||6.2||(10.3 predicted, +0.3)|
|2007.09||68.1 (1)||3.2 (2)||(11.5 predicted, +1.2)|
1) Running average based on the
daily 20:00 UTC observed solar flux
value at 2800 MHz.
2) Unofficial, accumulated value based on the Boulder (NOAA/SEC) sunspot number. The official international sunspot number is typically 30-50% lower.