Last major update issued on October 23, 2011 at 06:20 UTC.
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[POES auroral activity level since October
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Annotated geomagnetic activity charts - Carrington rotation 2113 [July-August 2011] - 2114 [August-September 2011]
[Solar polar fields vs solar cycles - updated June 27, 2011]
The geomagnetic field was very quiet on October 22. Solar wind speed ranged between 275 and 359 km/s.
Solar flux measured at 20h UTC on 2.8 GHz was 164.1 (decreasing 4.7 over the last solar rotation). The planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 2.8). Three hour interval K indices: 10001111 (planetary), 11001100 (Boulder).
The background x-ray flux is at the class B8 level.
At midnight UTC the visible solar disk had 13 spotted regions (in 2K resolution SDO images).
Region 11314 [rotated out of view at the northwest limb] produced a
very long duration M1.3 event peaking at 11:01 UTC. This event was associated
with a large and bright CME which was mostly northwards directed. LASCO images
indicated that the CME was very wide and became a partial halo CME.
Region 11317 [S26W77] was quiet and stable.
Region 11323 [N25W11] was quiet and stable.
Region 11324 [N14E16] decayed slowly and was mostly quiet. Flare: C4.1 at 15:20 UTC
Region 11325 [N16E43] decayed and lost penumbra on the trailing spots. Flare: C2.2 at 19:17, C1.7 at 20:43 UTC
Region 11326 [N16W63] decayed slowly and quietly.
Region 11327 [S20W13] decayed losing penumbra on the leading spots.
Region 11328 [N19W04] decayed slowly and was quiet.
Region 11329 [S30W54] decayed slowly and quietly.
New region 11330 [N08E72] rotated fully into view and has large leader and trailer spots. M class flaring is possible.
Spotted regions not reported by NOAA/SWPC:
[S1288] emerged in the southeast quadrant on October 22. Location at midnight: S15E08
[S1289] emerged in the northeast quadrant on October 22. Location at midnight: N20E17
[S1290] emerged in the northeast quadrant on October 22. Location at midnight: N17E05
[S1291] emerged in the northwest quadrant on October 22. Location at midnight: N11W46
October 20-21: No obviously Earth directed CMEs observed.
October 22: A full halo CME was observed after a large filament eruption in the northwest quadrant early in the day.
Coronal hole history (since late October
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A small coronal hole (CH480) in the northern hemisphere was in an Earth facing position on October 19-20.
The above coronal hole map is based on a new method where coronal holes are detected automatically. The method may need some fine tuning, however, it has significant advantages over detecting coronal holes manually. The main improvement is the ability to detect coronal holes at and just beyond the solar limbs. Early results using this method for SDO images over a span of several weeks indicate a good match between coronal holes observed over the visible disk and their extent and position at the east and west limbs. Note that the polar coronal holes are easily detected using the new method, the extent and intensity of both holes are consistent with other data sources.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is fair to good. Propagation on long distance northeast-southwest paths is poor.
The geomagnetic field is expected to be quiet to unsettled on October 23-24 due to weak coronal hole effects. On October 25 the CME observed on October 22 could arrive and cause unsettled to active conditions with a chance of minor storm intervals.
|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
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||N29W93||0090||HSX||rotated out of view|
|5||N13W89||0040||CSO||rotated out of view|
|Total spot count:||64||149|
|Sunspot number:||164||279||(total spot count + 10 * number of spotted regions)|
|Classification adjusted SN:||99||179||(Sum of total spot count + classification adjustment for each AR. Classification adjustment: X=0, R=3, A/S=5, H/K=10)|
|Relative sunspot number (Wolf number):||98||92||k * (sunspot number). k = 0.6 for SWPC. k = 0.33 for STAR SDO|
|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)|
|2010.07||79.8||16.1||16.7 (+0.3)||6.31 / 5.15|
|2010.08||79.2||19.6||17.4 (+0.7)||8.49 / 7.77|
|2010.09||81.1||25.2||19.6 (+2.2)||5.33 / 5.45|
|2010.10||81.6||23.5||23.2 (+3.6)||6.07 / 6.27|
|2010.11||82.5||21.5||26.5 (+3.3)||4.80 / 5.50|
|2010.12||84.2||14.4||28.8 (+2.3)||3.41 / 4.35|
|2011.01||83.6||19.1||31.0 (+2.2)||4.32 / 5.51|
|2011.02||94.6||29.4||33.4 (+2.4)||5.41 / 6.44|
|2011.03||115.0||56.2||36.9 (+3.5)||7.79 / 8.18|
|2011.04||112.6||54.4||(41.1 predicted, +4.2)||9.71 / 8.83|
|2011.05||95.8||41.6||(45.2 predicted, +4.1)||9.18 / 8.94|
|2011.06||95.8||37.0||(49.2 predicted, +4.0)||8.96|
|2011.07||94.2||43.9||(53.1 predicted, +3.9)||9.14|
|2011.08||101.7||50.6||(57.2 predicted, +4.1)||8.16|
|2011.09||133.8||78.0||(60.3 predicted, +3.1)||12.80|
|2011.10||137.7 (1)||88.9 (2A) / 125.2 (2B)||(61.8 predicted, +1.5)||(6.77)|
1) Running average based on the daily 20:00 UTC observed solar flux value at
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.