Last major update issued on November 26, 2007 at 04:45 UTC.
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The geomagnetic field was quiet to unsettled on November 25. Solar wind speed ranged between 556 and 669 km/s (average speed was 584 km/s, increasing 75 km/s over the previous day) under the influence of a high stream from CH300.
Solar flux measured at 20h UTC on 2.8 GHz was 70.7. The planetary A index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 11.4). Three hour interval K indices: 33322323 (planetary), 33323323 (Boulder).
The background x-ray flux is below the class A1 level.
At midnight there was 1 spotted region on the visible solar disk. The solar flare activity level was very low. No C class events were recorded during the day.
Region 10975 decayed slowly and quietly.
November 23-25: No obvious fully or partly Earth directed CMEs were observed in incomplete 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 small trans equatorial coronal hole (CH301) was in an Earth facing position on November 24-25. Another small trans equatorial coronal hole (CH30) could rotate into an Earth facing position on November 27-28.
Processed STEREO-B 195 image at 17:05 UTC on November 25. The darkest areas on the solar disk are likely coronal holes.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is poor. Propagation on long distance northeast-southwest paths is fair.
Monitoring remarks from a location near N58E06: November 12: During the evening fairly strong signals from east coast USA stations. 1470 WJDY, 1500 WFIF and 1520 WIZZ were all good on their daytime power. The best Trans Atlantic propagation sector was 270-310 degrees.
The geomagnetic field is expected to be quiet to unsettled on November 26 and quiet on November 27. A few unsettled and active intervals are possible on November 28 due to effects from CH301.
|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.
Data for all numbered solar regions according to the Solar Region Summary provided by NOAA/SEC. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SEC or where SEC has observed no spots. SEC active region numbers in the table below and in the active region map above are the historic SEC/USAF numbers.
|Active region||Date numbered||SEC
|Location at midnight||Area||Classification||Comment|
|10975||2007.11.24||2||2||N02W27||0010||BXO||classification was AXX at midnight|
|Total spot count:||2||2|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2007.05||74.4||11.7||(8.7 predicted, -1.2)|
|2007.06||73.7||12.0||(7.5 predicted, -1.2)|
|2007.07||71.6||10.0||(6.7 predicted, -0.8)|
|2007.08||69.1||6.2||(6.2 predicted, -0.5)|
|2007.09||67.1||2.4||(6.2 predicted, +0.0)|
|2007.10||67.4||0.9||(6.7 predicted, +0.5)|
|2007.11||69.2 (1)||2.1 (2)||(7.3 predicted, +0.6)|
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.
This report has been prepared by Jan Alvestad. It is based partly on my own observations and analysis, and partly on data from some of these solar data sources. All time references are to the UTC day. Comments and suggestions are always welcome.