Solar Terrestrial Activity Report

Last major update issued on November 12, 2010 at 05:30 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-24 (last update October 2, 2010)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update October 2, 2010)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update October 2, 2010)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports from January 2003 (last update October 9, 2010)]

[POES auroral activity level charts since October 2009]

Recent activity

The geomagnetic field was quiet to active on November 11. Solar wind speed ranged between 307 and 528 km/s under the influence of a high speed coronal hole stream.

Solar flux measured at 20h UTC on 2.8 GHz was 84.5 (up 2.3 over the last solar rotation). The planetary A index  was 15 (STAR Ap - based on the mean of three hour interval ap indices: 14.8). Three hour interval K indices: 31234324 (planetary), 31234324 (Boulder).

The background x-ray flux is at the class A8 level.

At midnight UTC the visible solar disk had 3 spotted regions.

Region 11123 decayed slowly losing some penumbral area. Flares: C2.9 at 02:14, C4.7 at 07:24, C4.3 at 16:16 and C1.1 at 19:30.
Region 11124 produced a couple of B9 flares and may be capable of C class flaring.
New region 11125 emerged in the northeast quadrant on November 10 and was numbered the next day by NOAA/SWPC.

Coronal mass ejections (CMEs)

November 9-11: No obviously Earth directed CMEs were seen in LASCO or STEREO images.

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

A trans equatorial coronal hole (CH427) was in an Earth facing position on November 11-12.

Image courtesy of SDO (NASA) and the AIA consortium. Annotations are my own. The darkest areas on the solar disk are likely coronal holes.

Propagation

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.

Forecast

The geomagnetic field is expected to be quiet to active on November 12. Quiet conditions are likely on November 13-14. Quiet to unsettled conditions are possible on November 15-16 due to effects from CH427.

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 (Recent map)

Compare to the previous day's image

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 (NASA) / AIA 4500
image
Comment
SWPC STAR SWPC STAR Current Previous
11121 2010.11.04     S23W28           plage
11122 2010.11.04     N12W66           plage
11123 2010.11.10 12 17 S22E03 0080 DAI CAI  
11124 2010.11.10 3 5 N16E27 0015 CAO CRO  
S835 2010.11.10     N18E14         spotless
11125 2010.11.11 3 4 N19E48 0015 CRO BXO  
Total spot count: 18 26  
SSN: 48 56  

Monthly solar cycle data

Month Average measured solar flux International sunspot number (SIDC) Smoothed sunspot number Average ap
(3)
2000.04 184.2 125.5 120.8
cycle 23 sunspot max.
 
2000.07 202.3 170.1 119.8  
2001.12 235.1 132.2 114.6 (-0.9)  
2008.07 65.7 (SF minimum) 0.5 2.8 (-0.4)  
2008.12 69.2 0.8 1.7 (-)
sunspot minimum
3.25
2009.08 67.3 0.0 4.8 (+1.2) 5.70 / 4.89
2009.09 70.5 4.3 6.2 (+1.4) 3.88 / 3.61
2009.10 72.6 4.8 7.1 (+0.9) 3.66 / 3.56
2009.11 73.6 4.1 7.6 (+0.5) 2.45 / 2.63
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 (15.4 predicted, +1.4) 9.18 / 8.15
2010.06 72.5 13.6 (16.8 predicted, +1.4) 8.17 / 6.85
2010.07 79.8 16.1 (18.4 predicted, +1.6) 6.31 / 5.15
2010.08 79.2 19.6 (19.6 predicted, +1.2) 8.49 / 7.77
2010.09 81.1 25.2 (20.9 predicted, +1.3) 5.33
2010.10 81.6 23.5 (23.2 predicted, +2.3) 6.07
2010.11 82.7 (1) 12.6 (2A) / 34.5 (2B) (26.2 predicted, +3.0) (3.52)

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 international sunspot number is typically 30-50% lower. 2B) Month average to date.
3) Running average based on the 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.