Last major update issued on January 21, 2007 at 02:15 UTC.
geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-23 (last update January 11, 2007)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update January 11, 2007)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update January 11, 2007)]
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[Archived reports (last update December 18, 2006)]
The geomagnetic field was quiet to unsettled on January 20. Solar wind speed ranged between 555 and 662 km/s (all day average 582 km/s - decreasing 36 km/s compared to the previous day) under the influence of a high speed stream from CH255.
Solar flux measured at 20h UTC on 2.8 GHz was 78.8. The planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.1). Three hour interval K indices: 31121122 (planetary), 32331122 (Boulder).
The background x-ray flux is at 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.
New region 10939 emerged very quickly early in the day in the southwest quadrant. While there isn't any obvious polarity intermixing at this point, C flares are possible.
January 18-20: No obvious partly or fully Earth directed CMEs were detected 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 (CH255) in the southern hemisphere was in an Earth facing position on January 12-16.
Processed SOHO/EIT 195 image at 02:02 UTC on January 20. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be mostly quiet on January 21-24.
|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.
Monitoring has been temporarily suspended (as of January 1, 2007).
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|
|10939||2007.01.20||8||17||S03W17||0100||CAI||classification was DAI at midnight, area 0170|
|Total spot count:||11||17|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2006.07||75.7||12.2||(15.0 predicted, -1.3)|
|2006.08||79.0||12.9||(14.9 predicted, -0.1)|
|2006.09||77.8||14.5||(14.7 predicted, -0.2)|
|2006.10||74.3||10.4||(13.5 predicted, -1.2)|
|2006.11||86.3||21.5||(12.1 predicted, -1.4)|
|2006.12||84.5||13.6||(11.7 predicted, -0.4)|
|2007.01||83.8 (1)||21.3 (2)||(11.9 predicted, +0.2)|
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.
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.