Last major update issued on January 23, 2012 at 05:50 UTC.
[Solar and geomagnetic data - last month (updated
[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-24 (last update January 2, 2012)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update Jauary 2, 2012)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update January 2, 2012)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update January 5, 2012)]
[POES auroral activity level since October
2009 - updated January 20, 2012]
Annotated geomagnetic activity charts - Carrington rotation 2117 [November-December 2011] - 2118 [December 2011 - January 2012]
[Solar polar fields vs solar cycles - updated June 27, 2011]
The geomagnetic field was quiet to minor storm on January 22. Solar wind speed ranged between 298 and 441 km/s. A strong solar wind shock was observed at ACE at 05:14 UTC, the arrival of the CME observed on January 19. The interplanetary magnetic field was strongly southwards during two intervals. The disturbance peaked during the 19-22h UTC interval when the planetary A index reached 67.
Solar flux measured at 20h UTC on 2.8 GHz was 141.0 (decreasing 4.6 over the last solar rotation). The planetary A index was 24 (STAR Ap - based on the mean of three hour interval ap indices: 6.1). Three hour interval K indices: 10445454 (planetary), 11445343 (Boulder).
The background x-ray flux is at the class B5 level.
At midnight UTC the visible solar disk had 11 spotted regions (in 2K resolution SDO images).
Region 11401 [N17W28] decayed slowly and remains capable of producing
occasional M flares. Flares: C7.1 at 02:57,
C2.2 at 08:54, C3.7 long duration event peaking at 12:55 UTC.
Region 11402 [N30W22] developed new spots and a magnetic delta structure in a new penumbra to the north of the major penumbra. The region could produce further M class flaring and maybe even an X class event. This region is the source of significant activity early on January 23. First a long duration M1.1 event peaked near 03:05 UTC, an event which may have triggered a major M8.7 long duration event peaking at 03:59 UTC. These events were associated with a huge CME in STEREO imagery and what appears to be a strong proton event.
Region 11405 [N12W10] decayed slowly and quietly.
Region 11407 [N18W40] decayed significantly and was quiet.
Region 11408 [N08E57] was quiet and stable.
Region 11409 [N17E38] was quiet and stable.
Spotted regions not reported (or interpreted differently) by NOAA/SWPC:
[S1441] rotated into view at the southeast limb on January 22. Location at midnight: S13E76
[S1442] emerged in the northeast quadrant on January 22. Location at midnight: N12E19
[S1443] emerged in the northeast quadrant on January 22. Location at midnight: N17E06
[S1444] emerged in the northern hemisphere near the central meridian on January 22. Location at midnight: N13W03
[S1445] emerged with a single tiny spot at a high latitude in the northern hemisphere on January 22. Location at midnight: N50E13
January 20-22: No obviously Earth directed CMEs were observed in LASCO and
January 23: A halo CME was observed after the M1.1 and M8.7 LDEs in region 11402.
Coronal hole history (since October
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A small coronal hole (CH495) in the southern hemisphere was in an Earth facing position on January 20. A large recurrent coronal hole (CH496) in the southern hemisphere could rotate into an Earth facing position on January 24-26. A new, very small coronal hole (CH497) was Earth facing on January 22.
The above coronal hole map is based on a method where coronal holes are detected automatically. While the method may need some fine tuning, it has significant advantages over detecting coronal holes manually. The main improvement is the ability to detect coronal holes at and just beyond the solar limbs. Early results using this method for SDO images over a span of several weeks indicate a good match between coronal holes observed over the visible disk and their extent and position at the east and west limbs. Note that the polar coronal holes are easily detected using this method, the extent and intensity of both CHs are consistent with other data sources.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is very poor. Propagation on long distance northeast-southwest paths is poor to fair.
The geomagnetic field is expected to be quiet to active on January 22 due to CME effects. Quiet to unsettled is likely on January 23. The CME observed early on January 23 could reach Earth sometime between late on January 24 and late on January 25 and could cause unsettled to major storm conditions.
|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
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) 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 4K continuum
image with magnetic polarity overlay
|Total spot count:||43||89|
|Sunspot number:||103||199||(total spot count + 10 * number of spotted regions)|
|Weighted penumbral SN:||73||123||(Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10)|
|Relative sunspot number (Wolf number):||62||90||k * (sunspot number). k = 0.6 for SWPC. k = 0.45 (changed from 0.33 on Nov.1, 2011) for STAR SDO|
|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)|
|2010.10||81.6||23.5||23.2 (+3.6)||6.07 / 6.27|
|2010.11||82.5||21.5||26.5 (+3.3)||4.80 / 5.50|
|2010.12||84.2||14.4||28.8 (+2.3)||3.41 / 4.35|
|2011.01||83.6||19.1||31.0 (+2.2)||4.32 / 5.51|
|2011.02||94.6||29.4||33.4 (+2.4)||5.41 / 6.44|
|2011.03||115.0||56.2||36.9 (+3.5)||7.79 / 8.18|
|2011.04||112.6||54.4||41.8 (+4.9)||9.71 / 8.83|
|2011.05||95.8||41.6||47.6 (+5.8)||9.18 / 8.94|
|2011.06||95.8||37.0||53.2 (+5.6)||8.96 / 8.06|
|2011.07||94.2||43.9||(57.8 projected, +4.6)||9.14 / 8.16|
|2011.08||101.7||50.6||(62.0 projected, +4.2)||8.16 / 7.26|
|2011.09||133.8||78.0||(65.3 projected, +3.3)||12.80 / 12.27|
|2011.10||137.3||88.0||(68.8 projected, +3.5)||7.52|
|2011.11||153.5||96.7||(73.2 projected, +4.3)||4.58|
|2011.12||141.3||73.0||(78.6 projected, +5.5)||3.32|
|2012.01||135.8 (1)||66.1 (2A) / 97.8 (2B)||(84.4 projected, +5.8)||(5.41)|
1) Running average based on the daily 20:00 UTC observed solar flux value at
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days). The official SIDC 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.