Last major update issued on March 12, 2011 at 06:15 UTC.
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Annotated geomagnetic activity charts - Carrington rotation 2105 [Dec-Jan.2011] - 2106 [Jan.-Feb.2011]
NEW
The geomagnetic field was quiet to major storm on March 11 due to CME effects. Solar wind speed was in the range 323-467 km/s. Early on March 12 solar wind parameters suggest there has been a transition from a CME to a high speed coronal hole stream as the dominant solar wind source.
Solar flux measured at 20h UTC on 2.8 GHz was 123.1 (increasing 27.5 over the last solar rotation). The planetary A index was 40 (STAR Ap - based on the mean of three hour interval ap indices: 40.0). Three hour interval K indices: 45422566 (planetary), 44432445 (Boulder).
The background x-ray flux is at the class B7 level.
At midnight UTC the visible solar disk had 6 spotted regions.
Region 11166 decayed in the trailing spot section. Generally speaking
there is less polarity intermixing compared to one day ago, however, M class
flares are possible. Flares: C2.8 at 02:29, C5.5 at 04:32, C3.0 at
07:03, C4.3 at 07:27, C2.0 at 11:15, C3.6 at 11:47, C1.1 at 16:07, C1.0 at 22:20
and C1.0 at 22:43 UTC. The region produced an M1.3 flare at 04:43 UTC on March
12.
Region 11169 decayed in the trailing spot section with a few of the
remaining spots having rudimentary penumbra.
Region 11171 added several tiny spots.
New region 11172 rotated fully into viw at the northeast limb.
Spotted regions not numbered by NOAA/SWPC:
[S900] Tiny spots emerged in an old plage area in the southeastern
quadrant on March 8. Slow development was observed on March 11. Location at midnight:
S18W12.
[S902] A few spots emerged in the northeast quadrant on March 10. Those
spots disappeared on March 11 while new spots formed further south.
Location at midnight: N08E21.
March 9-11: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
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
An extension (CH439) of the southern polar coronal hole was Earth facing on March 10.
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 very poor. Propagation on long distance northeast-southwest paths is poor to fair.
The geomagnetic field is expected to be quiet to minor storm on March 12 due to CME and coronal hole effects. On March 13-14 quiet to unsettled conditions are possible as a stream from CH439 will be the main solar wind source.
| 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 detected |
Spot count | Location at midnight | Area | Classification | SDO / HMI 4K continuum image with polarity overlay |
Comment | |||
|---|---|---|---|---|---|---|---|---|---|---|
| SWPC | STAR SDO | SWPC | STAR | Current | Previous | |||||
| 11166 | 2011.03.02 | 47 | 57 | N09W39 | 0690 | EKC | EKC |
 |
 |
beta-gamma-delta |
| 11167 | 2011.03.02 2011.03.03 |
N12W80 |
 |
plage location: N12W76 |
||||||
| 11169 | 2011.03.05 2011.03.06 |
26 | 37 | N20W09 | 0250 | EKI | CKI |
 |
 |
|
| S895 | 2011.03.05 | N07W66 | plage | |||||||
| S896 | 2011.03.06 | N16W47 |
 |
plage | ||||||
| S898 | 2011.03.07 | S13W02 | plage | |||||||
| S899 | 2011.03.07 | N19W43 | plage | |||||||
| 11171 | 2011.03.08 | 11 | S20E17 | 0010 | BXO |
 |
 |
location of spots: S20E17 | ||
| S900 | 2011.03.08 | 3 | S18W12 | 0010 | BXO |
 |
 |
|||
| S901 | 2011.03.08 | S22W53 | plage | |||||||
| S902 | 2011.03.10 | 3 | N08E21 | 0010 | BXO |
 |
 |
|||
| 11172 | 2011.03.10 2011.03.11 |
2 | 2 | N11E72 | 0010 | BXO | AXX |
 |
 |
formerly region S903 |
| Total spot count: | 75 | 113 | ||||||||
| Sunspot number: | 105 | 173 | ||||||||
| 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 |
| 2009.12 | 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 | 17.4 (+0.6) | 8.49 / 7.77 |
| 2010.09 | 81.1 | 25.2 | (19.1 predicted, +1.7) | 5.33 / 5.45 |
| 2010.10 | 81.6 | 23.5 | (21.7 predicted, +2.6) | 6.07 / 6.27 |
| 2010.11 | 82.5 | 21.6 | (24.5 predicted, +2.8) | 4.80 / 5.50 |
| 2010.12 | 84.2 | 14.5 | (26.9 predicted, +2.4) | 3.41 / 4.35 |
| 2011.01 | 83.6 | 19.1 | (29.0 predicted, +2.1) | 4.32 |
| 2011.02 | 94.6 | 29.4 | (31.1 predicted, +2.1) | 5.41 |
| 2011.03 | 131.6 (1) | 37.0 (2A) / 104.2 (2B) | (33.0 predicted, +1.9) | (14.47) |
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.
