Last major update issued on January 27, 2011 at 05:45 UTC.
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[Archived reports from January 2003 (last update January
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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 26. Solar wind speed ranged between 280 and 319 km/s.
Solar flux measured at 20h UTC on 2.8 GHz was 80.0 (decreasing 2.9 over the last solar rotation). The planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 3.1). Three hour interval K indices: 11100111 (planetary), 11200220 (Boulder).
The background x-ray flux is at the class A7 level.
At midnight UTC the visible solar disk had 3 spotted regions.
Region 11147 was quiet and stable.
Region 11149 decayed further losing all trailing spots.
Spotted regions not numbered by NOAA/SWPC:
[S865] This region emerged in the northwest quadrant on January 26.
Location at midnight: N11W31
January 24-26: 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. A trans equatorial area with weak corona may be numbered today.
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 27-28. On January 29-30 there's a chance of a few unsettled intervals due to a weak trans equatorial coronal hole.
| 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.
(Click on image for higher resolution image with polarity overlay) 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 |
Comment | |||
|---|---|---|---|---|---|---|---|---|---|---|
| SWPC | STAR | SWPC | STAR | Current | Previous | |||||
| 11147 | 2011.01.15 | 1 | 1 | N24W77 | 0150 | HSX | HSX |
 |
 |
area: 0100 |
| 11149 | 2011.01.21 | 4 | 4 | N17W77 | 0130 | DSO | HSX |
 |
 |
area: 0130 |
| S865 | 2011.01.26 | 1 | N11W31 | 0010 | AXX |
 |
||||
| Total spot count: | 5 | 6 | ||||||||
| Sunspot number: | 25 | 36 | ||||||||
| Month | Average measured solar flux | International sunspot number (SIDC) | Smoothed sunspot number | Average ap (3) |
|---|---|---|---|---|
| 2008.07 | 65.7 (SF minimum) | 0.5 | 2.8 (-0.4) | |
| 2008.12 | 69.2 | 0.8 | 1.7 (-) sunspot minimum |
3.25 |
| 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 | 84.0 (1) | 29.1 (2A) / 34.7 (2B) | (27.7 predicted, +2.4) | (4.51) |
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.
