Last major update issued on March 2, 2011 at 05:15 UTC.
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[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-24 (last update March 2, 2011)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update March 2, 2011)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update March 2, 2011)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
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[POES auroral activity level charts since October
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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 1. Solar wind speed ranged between 276 and 501 km/s. The solar wind disturbance had two stages, during the first half of the day solar wind speed was fairly low and under the influence of effects from CH437. During the latter half of the day a much stronger disturbance was observed as CH438 became the dominant solar wind originator.
Solar flux measured at 20h UTC on 2.8 GHz was 110.5 (increasing 31.3 over the last solar rotation). The planetary A index was 31 (STAR Ap - based on the mean of three hour interval ap indices: 30.9). Three hour interval K indices: 22245654 (planetary), 22345544 (Boulder).
The background x-ray flux is at the class B5 level.
At midnight UTC the visible solar disk had 5 spotted regions.
Region 11163 was quiet and stable.
Region 11164 changed a lot during the day. Early on there was a magnetic delta structure in a central penumbra, however, this penumbra appeared to disintegrate during the long duration C6 event. Growth was observed elsewhere in the region, which now has a large extent both latitudinally and longitudinally. Although the region at the time of writing does not have as complex a magnetic layout as it had recently, there's still a fair chance of a major flare. Flares: long duration C6.0 event peaking at 04:13, C2.9 at 09:18, C1.1 at 14:38, C1.0 at 16:47, C1.3 at 17:47, C1.0 at 18:19, C1.6 at 19:57 UTC.
Region 11165 displayed no significant changes.
Spotted regions not numbered by NOAA/SWPC:
[S888] This region emerged early on February 28 in the southeast quadrant. The region decayed on March and could soon become spotless. Location at midnight: S17W10
[S889] A tiny spot emerged in this region on March 1. Location at midnight: S04W44.
February 27 - March 1: 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 very poor. Propagation on long distance northeast-southwest paths is fair.
The geomagnetic field is expected to be quiet to minor storm on March 2-3 due to effects from CH438, quiet to unsettled is likely on March 4.
|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:||42||64|
|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||110.5 (1)||2.3 (2A) / 72 (2B)||(28.9 predicted, +1.9)||(30.88)|
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.