Solar Terrestrial Activity Report

Last major update issued on November 10, 2011 at 05:55 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-24 (last update November 1, 2011)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update November 1, 2011)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update November 1, 2011)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update November 2, 2011)]

[POES auroral activity level since October 2009 - updated November 7, 2011]
Annotated geomagnetic activity charts - Carrington rotation 2114 [August-September 2011] - 2115 [September-October 2011]
[Solar polar fields vs solar cycles - updated June 27, 2011]

Recent activity

The geomagnetic field was quiet on November 9. Solar wind speed ranged between 326 and 407 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 180.2 (increasing 42.6 over the last solar rotation). The planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 2.1). Three hour interval K indices: 00001211 (planetary), 00001221 (Boulder).

The background x-ray flux is at the class B7 level.

At midnight UTC the visible solar disk had 10 spotted regions (in 2K resolution SDO images).

Region 11338 [S13W38] decayed slowly and quietly.
Region 11339 [N19W22] decayed slowly and was mostly quiet.
Region 11340 [S08E11] was quiet and stable.
Region 11341 [N10E27] was quiet and stable.
Region 11342 [N17E18] decayed slowly and quietly
Region 11343 [N27E38] was quiet and stable.
Region 11344 [S23W21] decayed slowly and could soon become spotless.
New region 11345 [S25W02] emerged and developed moderately quickly. C flares are possible.

Spotted regions not reported by NOAA/SWPC:
[S1315] emerged in the southeast quadrant on November 8. Location at midnight: S20E25
[S1317] emerged in the southern hemisphere near the central meridian on November 8 and developed slowly on Nov.9. Location at midnight: S17W16

A large filament eruption was observed in the southern hemisphere starting at 08:44 UTC in SDO/AIA 193 images. The associated CME does not appear to have any Earth directed component. Another filament eruption was associated with an M1.1 long duration event peaking at 13:35 UTC. This event occurred between regions 11342 and 11343. The associated CME was wide and could reach Earth on November 12.

Coronal mass ejections (CMEs)

November 7-8: No obviously Earth directed CMEs observed.
November 9: An apparently Earth directed CME was observed after a filament eruption in the northeast quadrant.

Coronal holes

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 obvious coronal holes are near Earth facing positions.

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.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on November 10-11. The CME observed on Nov.9 will likely reach Earth on Nov.12 and cause unsettled to minor storm conditions.

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.

Active solar regions

(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
11336 2011.10.29
2011.10.31
2   N14W69 0001 AXX     spotless
11337 2011.10.30
2011.10.31
1   N17W57 0001 AXX     spotless
11338 2011.10.31
2011.11.01
11 14 S12W38 0230 DSO CSO

 

11339 2011.11.01 50 67 N21W19 1030 FKC EKC beta-gamma-delta
11344 2011.11.03
2011.11.07
10 5 S22W19 0040 DAO BXO area: 0000
11340 2011.11.04
2011.11.05
1 1 S09E09 0090 HSX HSX area: 0150
S1311 2011.11.04     N16W40           plage
11341 2011.11.05 8 8 N18E28 0210 DSO CSO location: N10E27
11342 2011.11.05 18 13 N17E22 0310 EHO CHO  
11343 2011.11.05
2011.11.06
1 2 N27E37 0110 HSX HSX  
S1314 2011.11.07     N20W03           plage
S1315 2011.11.08   2 S20E25 0000   AXX  
S1316 2011.11.08     N03W05         plage
S1317 2011.11.08   12 S17W16 0040   CAO  
11345 2011.11.09 6 12 S25W01 0080 CSO DRO  

area: 0050

Total spot count: 108 136  
Sunspot number: 208 236  (total spot count + 10 * number of spotted regions)
Classification adjusted SN: 158 184  (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): 125 106  k * (sunspot number). k = 0.6 for SWPC. k = 0.45 (changed from 0.33 on Nov.1) for STAR SDO

Monthly solar cycle data

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
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  168.7 (1) 42.2 (2A) / 140.6 (2B) (74.9 predicted, +4.4) (6.49)

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.