Last major update issued on March 3, 2011 at 05:10 UTC. Minor update posted at 16:15 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 active on March 2 under the influence of a high speed stream from CH438.
Solar flux measured at 20h UTC on 2.8 GHz was 113.4 (increasing 33.0 over the last solar rotation). The planetary A index was 17 (STAR Ap - based on the mean of three hour interval ap indices: 16.6). Three hour interval K indices: 44323333 (planetary), 44322323 (Boulder).
The background x-ray flux is at the class B4 level.
At midnight UTC the visible solar disk had 5 spotted regions.
Region 11163 decayed slowly and quietly.
Region 11164 lost quite a few spots. The main penumbra is large (spanning
about 5 degrees longitudinally) and has a weak magnetic delta structure at its
northwestern flank. An M class flare is still possible
Flare: C1.4 at 13:18 UTC.
Region 11165 decayed slowly and was quiet.
New region 11166 began to rotate into view early in the day at the
northeast limb. The region could produce C flares and maybe minor M class
flares.
Spotted regions not numbered by NOAA/SWPC:
[S890] This region emerged in the northeast quadrant on March 2. Location at midnight:
N14E45.
Minor update added at 16:15 UTC: Two new regions have emerged on the visible disk. See this updated map.
February 28 - March 2: 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
A large trans equatorial coronal hole (CH438) was Earth facing on February 27 - March 1.
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 poor. Propagation on long distance northeast-southwest paths is fair.
The geomagnetic field is expected to be quiet to unsettled on March 3-4 due to effects from CH438, isolated active intervals are possible. Quiet conditions are likely on March 5-6.
| 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 | |||||
| 11163 | 2011.02.24 | 6 | N17W08 | 0000 | AXX |
 |
 |
|||
| 11164 | 2011.02.25 | 41 | 34 | N25E08 | 0400 | EKC | FKI |
 |
 |
beta-gamma-delta area: 0800 |
| 11165 | 2011.02.26 2011.02.25 |
11 | 7 | S22W09 | 0030 | BXO | BXO |
 |
 |
area: 0010 |
| S888 | 2011.02.28 | S17W23 |
 |
plage | ||||||
| S889 | 2011.03.01 | S04W57 |
 |
plage | ||||||
| 11166 | 2011.03.02 | 1 | 8 | N10E77 | 0010 | HRX | ESO |
 |
area: 0300 location: N08E82 |
|
| S890 | 2011.03.02 | 5 | N14E45 | 0010 | CRO |
 |
||||
| Total spot count: | 53 | 60 | ||||||||
| Sunspot number: | 83 | 110 | ||||||||
| 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 | (18.5 predicted, +1.1) | 5.33 / 5.45 |
| 2010.10 | 81.6 | 23.5 | (20.1 predicted, +1.6) | 6.07 / 6.27 |
| 2010.11 | 82.5 | 21.6 | (21.9 predicted, +1.8) | 4.80 / 5.50 |
| 2010.12 | 84.2 | 14.5 | (23.6 predicted, +1.7) | 3.41 / 4.35 |
| 2011.01 | 83.6 | 19.1 | (25.4 predicted, +1.8) | 4.32 |
| 2011.02 | 94.6 | 29.4 | (27.0 predicted, +1.6) | 5.41 |
| 2011.03 | 112.0 (1) | 5.0 (2A) / 77.5 (2B) | (28.9 predicted, +1.9) | (23.75) |
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.
