Last major update issued on January 21, 2011 at 04:50 UTC.
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[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-24 (last update January 2, 2011)]
[Solar cycles 1-20]
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[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports from January 2003 (last update January 1, 2011)]
[POES auroral activity level
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Annotated geomagnetic activity charts - Carrington rotation 2104 [Nov-Dec.2010]- 2105 [Dec-Jan.2011] NEW
The geomagnetic field was quiet on January 20. Solar wind speed ranged between 418 and 472 km/s, weakly under the influence of a high speed stream associated with CH434.
Solar flux measured at 20h UTC on 2.8 GHz was 82.3 (increasing 3.7 over the last solar rotation). The planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 3.4). Three hour interval K indices: 01222000 (planetary), 11232110 (Boulder).
The background x-ray flux is at the class A6 level.
At midnight UTC the visible solar disk had 3 spotted regions.
Region 11147 decayed slowly and was mostly quiet.
Region 11148 decayed slowly and quietly.
Spotted regions not numbered by NOAA/SWPC:
[S863] This region emerged to the south of region 11147 and developed quickly late on January 20. The region has an interesting magnetic layout and could produce further C flares (the first one was observed at 04:15 UTC on January 21, a C3.3 event). Location at midnight: N18E08
January 18-20: No obviously Earth directed CMEs were observed in LASCO or STEREO images.
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
No significant coronal holes are currently Earth facing.
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 21-23.
|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
When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue (blue-green) is positive.
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||Spot count||Location at midnight||Area||Classification||SDO / HMI continuum
image with polarity overlay
|Total spot count:||12||16|
|Month||Average measured solar flux||International sunspot number (SIDC)||Smoothed sunspot number||Average ap
|2008.07||65.7 (SF minimum)||0.5||2.8 (-0.4)|
|2009.10||72.6||4.8||7.1 (+0.9)||3.66 / 3.56|
|2009.11||73.6||4.1||7.6 (+0.5)||2.45 / 2.63|
|2009.12||76.7||10.8||8.3 (+0.7)||1.41 / 1.92|
|2010.01||81.1||13.2||9.3 (+1.0)||2.93 / 3.07|
|2010.02||84.7||18.8||10.6 (+1.3)||4.15 / 4.61|
|2010.03||83.4||15.4||12.3 (+1.7)||4.58 / 4.65|
|2010.04||75.9||8.0||14.0 (+1.7)||10.22 / 10.24|
|2010.05||73.8||8.7||15.5 (+1.5)||9.18 / 8.15|
|2010.06||72.5||13.6||16.4 (+0.9)||8.17 / 6.85|
|2010.07||79.8||16.1||(17.0 predicted, +0.6)||6.31 / 5.15|
|2010.08||79.2||19.6||(17.9 predicted, +0.9)||8.49 / 7.77|
|2010.09||81.1||25.2||(19.0 predicted, +1.1)||5.33 / 5.45|
|2010.10||81.6||23.5||(20.7 predicted, +1.7)||6.07 / 6.27|
|2010.11||82.5||21.6||(23.0 predicted, +2.3)||4.80|
|2010.12||84.2||14.5||(25.3 predicted, +2.3)||3.41|
|2011.01||84.2 (1)||22.7 (2A) / 35.3 (2B)||(27.7 predicted, +2.4)||(5.00)|
1) Running average based on the
daily 20:00 UTC observed solar flux
value at 2800 MHz.
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days). The official international sunspot number is typically 30-50% lower. 2B) Month average to date.
3) Running average based on the preliminary daily SWPC ap indices. Values in red are based on the official NGDC ap indices.
This report has been prepared by Jan Alvestad. It is based on analysis of data from whatever sources are available at the time the report is prepared. All time references are to the UTC day. Comments and suggestions are always welcome.
SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.