Last major update issued on November 20, 2011 at 06:00 UTC.
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Annotated geomagnetic activity charts - Carrington rotation 2114 [August-September 2011] - 2115 [September-October 2011]
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The geomagnetic field was very quiet on November 19. Solar wind speed ranged between 320 and 361 km/s.
Solar flux measured at 20h UTC on 2.8 GHz was 139.6 (decreasing 15.9 over the last solar rotation). The planetary A index was 1 (STAR Ap - based on the mean of three hour interval ap indices: 1.1). Three hour interval K indices: 00000101 (planetary), 00001001 (Boulder).
The background x-ray flux is at the class B6 level.
At midnight UTC the visible solar disk had 12 spotted regions (in 2K resolution SDO images).
Region 11346 [S17W27] decayed slowly and quietly. There's still minor
Region 11350 [N27E04] decayed and could become spotless today.
Region 11352 [S23E29] was quiet and has minor polarity intermixing.
Region 11353 [N08E47] was quiet and stable.
Region 11354 [S14E45] developed with a weak magnetic delta structure forming in a central penumbra. C flares are likely and there's a chance of a minor M class flare. Flares: C1.4 at 11:25, C3.9 at 19:55, C1.6 at 20:52 UTC
Region 11355 [N15E60] could be forming a weak magnetic delta structure at the southeastern edge of the single penumbra. Flare: C1.7 at 07:57 UTC
New region 11356 [N16E85] rotated partly into view at the northeast limb. There could be a magnetic delta structure in the leading penumbra. M flares are possible. Flare: C4.5 at 22:28 UTC
Spotted regions not reported by NOAA/SWPC:
[S1327] emerged in the southeast quadrant on November 16. Location at midnight: S25E11
[S1331] emerged in the northeast quadrant on November 17. New flux began emerging on Nov.19 and the region is still developing early on Nov.20. Location at midnight: N19W04
[S1332] rotated into view at the northeast limb on November 18. Location at midnight: N24E64
[S1333] emerged in the northeast quadrant on November 19. Location at midnight: N12E35
[S1334] emerged in the northeast quadrant on November 19. Location at midnight: N18E19
November 17-19: No obviously Earth directed CMEs observed.
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 poorly defined trans equatorial coronal hole (CH485) was in an Earth facing position on November 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 on November 20-21. On Nov.22-23 there's a chance of unsettled intervals due to effects from CH485.
|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 magnetic polarity overlay
rotated out of view
|11351||2011.11.14||2||S24W17||0010||HRX||region should be deleted, these are the trailing spots of region 11346|
|Total spot count:||39||115|
|Sunspot number:||149||235||(total spot count + 10 * number of spotted regions)|
|Classification adjusted SN:||82||148||(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):||89||106||k * (sunspot number). k = 0.6 for SWPC. k = 0.45 (changed from 0.33 on Nov.1) 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||41.8 (+4.9)||9.71 / 8.83|
|2011.05||95.8||41.6||(47.4 predicted, +5.6)||9.18 / 8.94|
|2011.06||95.8||37.0||(52.5 predicted, +5.1)||8.96 / 8.06|
|2011.07||94.2||43.9||(58.2 predicted, +5.7)||9.14 / 8.16|
|2011.08||101.7||50.6||(63.7 predicted, +5.5)||8.16 / 7.26|
|2011.09||133.8||78.0||(67.0 predicted, +3.3)||12.80 / 12.27|
|2011.10||137.3||88.0||(70.5 predicted, +3.5)||7.52|
|2011.11||162.0 (1)||88.8 (2A) / 140.3 (2B)||(74.9 predicted, +4.4)||(4.18)|
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.