Last major update issued on February 17, 2011 at 05:30 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-24 (last update February 1, 2011)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update February 1, 2011)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update February 1, 2011)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update February 1, 2011)]
[POES auroral activity level
charts since October 2009]
Annotated geomagnetic activity charts - Carrington rotation 2104 [Nov-Dec.2010]- 2105 [Dec-Jan.2011] NEW
The geomagnetic field was quiet on February 16. Solar wind speed ranged between 350 and 459 km/s.
Solar flux measured at 20h UTC on 2.8 GHz was 114.1 (increasing 31.8 over the last solar rotation - and a new high for cycle 24). The planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 1.5). Three hour interval K indices: 02000001 (planetary), 02111110 (Boulder).
The background x-ray flux is at the class B8 level.
At midnight UTC the visible solar disk had 6 spotted regions.
Region 11157 decayed slowly and will rotate to the northwest limb
Region 11158 lost some of its complexity in the central spot section as the largest penumbra split. There was some decay in the trailing spot section as well. The region could still produce another major flare. Flares: C2.0 at 01:05, M1.0 at 01:39, C2.2 at 02:00, C5.9 at 05:45, C2.2 at 06:22, M1.1 at 07:44, C9.9 at 09:11, C3.2 at 10:32, C1.0 at 12:02, M1.6/1F at 14:25 (associated with a strong type II radio sweep), C7.7 at 15:32, C1.3 at 19:36, C1.1 at 20:15, C4.2 at 21:10 and C1.5 at 23:06 UTC.
Region 11160 developed slowly and could produce an M class flare.
Spotted regions not numbered by NOAA/SWPC:
[S875] This region in the northeast quadrant reemerged on February 13 and has displayed no significant changes since then. Location at midnight: N20W25
[S878] This region emerged in the northeast quadrant on February 13. Location at midnight: N19E08
[S880] This region reemerged with tiny spots on February 16. Location at midnight: N07W23
February 14: A CME was observed in association with an M2 event in region
11158 and could reach Earth on February 17.
February 15: The X2 event in region 11158 was associated with a full halo CME. The CME could reach Earth on February 17.
February 16: No Earth directed CMEs were observed. A filament eruption in region S878 around 06-07 UTC produced a CME off the northeast limb.
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 in or near Earth facing positions.
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 to major storm on February 17-18 due to CME effects and quiet to unsettled on February 19.
|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) 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 polarity overlay
|Total spot count:||30||83|
|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)|
|2009.11||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||16.8 (+0.4)||6.31 / 5.15|
|2010.08||79.2||19.6||(17.1 predicted, +0.3)||8.49 / 7.77|
|2010.09||81.1||25.2||(17.7 predicted, +0.6)||5.33 / 5.45|
|2010.10||81.6||23.5||(19.0 predicted, +1.3)||6.07 / 6.27|
|2010.11||82.5||21.6||(20.7 predicted, +1.7)||4.80 / 5.50|
|2010.12||84.2||14.5||(22.2 predicted, +1.5)||3.41 / 4.35|
|2011.01||83.6||19.1||(23.8 predicted, +1.6)||4.32|
|2011.02||91.7 (1)||29.6 (2A) / 51.9 (2B)||(25.5 predicted, +1.7)||(5.91)|
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 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.