Last major update issued on March 5, 2011 at 07:20 UTC. Minro update posted at 16:05 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 unsettled on March 4 under the influence of a high speed stream from CH438.
Solar flux measured at 20h UTC on 2.8 GHz was 126.8 (increasing 45.8 over the last solar rotation). The planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 10.5). Three hour interval K indices: 23322223 (planetary), 23332322 (Boulder).
The background x-ray flux is at the class B7 level.
At midnight UTC the visible solar disk had 8 spotted regions.
Region 11163 was quiet and stable.
Region 11164 developed a weak magnetic delta structure and has major flare potential. Taking into consideration the complexity of the region, it has displayed surprisingly little activity. Flares: C1.7 at 14:00, C1.0 at 17:19 UTC.
Region 11165 was quiet and stable.
Region 11166 developed significantly with a magnetic delta structure forming in a new and quickly expanding central penumbra. The region is compact and could produce a major flare.
Region 11167 was quiet and didn't change significantly.
New region 11168 emerged in the northwest quadrant on March 3 and was numbered the next day by NOAA/SWPC. The region decayed and lost the trailing spots.
Spotted regions not numbered by NOAA/SWPC:
[S891] This region emerged in the southwest quadrant on March 3. Slow development was observed on March 4 and the region currently has polarity intermixing. Location at midnight: S17W41. Unfortunately SWPC seems to regard S891 and 11165 as a single region, this interpretation is not supported by SDO data.
[S893] Tiny spots emerged in a plage area in the northeast quadrant on March 3 with slow decay observed on March 4. Location at midnight: N20E09.
Minor update added at 16:05 UTC: Region 11164 is still developing fairly quickly while region 11166 appears to be less complex now than it was a few hours ago. Here's the latest active region map. A new region (S894) has rotated into view at the northeast limb while spots have emerged in a new region (S895) to the southeast of region 11167. Just north of region 11166 another emerging region is visible and could soon develop spots.
March 2 and 4: No obviously Earth directed CMEs were observed in LASCO and
March 3: A partial halo CME was observed in LASCO and STEREO images after 05:30 UTC. There was no apparent filament eruption and the source of this CME appears to have been to the southeast of the center of the visible disk.
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 an Earth facing position.
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 5 due to effects from CH438. On March 6 or 7 there is a chance the CME observed on March 3 will cause some unsettled and active intervals, if the CME fails to arrive quiet conditions are likely.
|Coronal holes (1)||Coronal mass ejections (2)||M and X class flares (3)|
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
|1||1||N24W73||0000||AXX||formerly region S892|
|Total spot count:||54||123|
|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)|
|2009.12||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||117.9 (1)||10.6 (2A) / 82.5 (2B)||(28.9 predicted, +1.9)||(17.63)|
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.