Last major update issued on January 12, 2010 at 04:10 UTC.
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The geomagnetic field was quiet on January 11. Solar wind speed ranged between 273 and 596 km/s. A high speed stream, likely from CH388, began to influence the field early in the day and apparently peaked around 15h UTC. This stream arrived earlier and was faster than expected.
Solar flux measured at 20h UTC on 2.8 GHz was 89.2. The planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.1). Three hour interval K indices: 02222211 (planetary), 0232331* (Boulder).
The background x-ray flux is at the class B1 level.
At midnight there was 1 spotted region on the visible solar disk.
Region 11040 continue to develop fairly quickly and is capable of producing an isolated M class flare.
January 9-11: No partially or fully Earth directed CMEs were observed in LASCO or STEREO imagery.
Coronal hole 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 coronal hole (CH388) in the northern hemisphere rotated across the central meridian on January 9.
Processed SOHO/EIT 195 image at 16:36 UTC on January 11. 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 fair. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet on January 12-15 with a chance of unsettled intervals on January 12.
|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/SWPC. 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 SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers.
|Active region||Date numbered||SWPC
|Location at midnight||Area||Classification||Comment|
|Total spot count:||*||25|
|Month||Average measured solar flux||International sunspot number (SIDC)||Smoothed sunspot number||Average Ap|
cycle 23 sunspot max.
|2009.07||68.2||3.5||(3.5 predicted, +0.8)||5.49|
|2009.08||67.3||0.0||(4.4 predicted, +0.9)||5.70|
|2009.09||70.5||4.2||(5.4 predicted, +1.0)||3.88|
|2009.10||72.6||4.6||(6.5 predicted, +1.1)||3.66|
|2009.11||73.6||4.2||(7.7 predicted, +1.2)||2.45|
|2009.12||76.7||10.6||(9.1 predicted, +1.4)||1.41|
|2010.01||79.0 (1)||6.3 (2)||(10.1 predicted, +1.0)||(1.86)|
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/SWPC) 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.