Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 11, 2013 at 04:45 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update November 2, 2013)] [Cycle 24 progress (last update November 2, 2013) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update November 2, 2013)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update November 2, 2013)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update November 3, 2013)]

[POES auroral activity level since October 2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated November 2, 2013]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet to unsettled on November 10. Solar wind speed at SOHO ranged between 480 and 666 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 154.1 (increasing 29.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 121.9. The Potsdam WDC planetary A index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 10.6). Three hour interval K indices: 33222233 (planetary), 22232333 (Boulder).

The background x-ray flux was at the class B9 level.

At the time of counting spots (see image time) spots were observed in 10 active regions in 2K resolution (SN: 210) and 7 active regions in 1K resolution (SN: 119) SDO images on the visible solar disk.

Region 11890 [S11W29] decayed slowly and still has a magnetic delta structure in a southeastrern penumbra. Another major flare is possible. C5+ flare:  major X1.1 flare at 05:14 UTC. A small CME was observed after this event.
Region 11892 [S07E12] was quiet and stable.
Region 11893 [S13E42] developed slowly and was quiet.
New region 11895 [S18E75] began to rotate into view on Nov.9 and appears to be a large region capable of producing major flares. It is not yet clear if the spots should be split into several regions or if this is one region.
New region 11896 [N10E75] rotated into view with one spot.

Spotted regions not numbered by SWPC:
S2796 [N05W65] decayed slowly and quietly and lost the trailer spot.
S2803 [N06W29] was quiet and stable.
S2816 [S26W17] regained a leading polarity penumbra spot and lost the trailing spots.
S2819 [S27E26] developed slowly and quietly.
New region S2826 [S25E10] emerged with several penumbra spots.

Coronal mass ejections (CMEs)

November 10: Only a small CME was observed after the X1 flare in AR 11890. As most of the ejected material was observed off the south pole it is uncertain if the CME will have any terrestrial effects.
November 9: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
November 8: A full halo CME was observed after the X1 event in AR 11890 early in the day. The CME may have reached Earth early on November 10 embedded in a high speed coronal hole stream.

Coronal holes

Coronal hole history (since October 2002)
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago

A recurrent trans equatorial coronal hole (CH593) was in an Earth facing position on November 7-8. A coronal hole (CH594) in the northern hemisphere will likely rotate into an Earth facing position on November 12-13.

Coronal hole map

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 to good.

Forecast

The geomagnetic field is expected to be quiet to minor storm on November 11-12 due to CME and coronal hole effects.

Coronal holes (1) Coronal mass ejection (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 2K resolution) Compare to the previous day's image. 0.5K image

When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue 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 magnetic polarity overlay
Comment
SWPC STAR SDO SWPC STAR Current Previous
2K 1K
11887 2013.10.29
2013.10.30
2     N18W84 0010 BXO    

 

S2796 2013.10.31   1   N05W65 0003   AXX  
11890 2013.11.01
2013.11.02
28 75 31 S12W28 0530 EKC EHC beta-gamma-delta
11889 2013.11.02       S18W82           plage
S2800 2013.11.02       S08W45           plage
S2803 2013.11.03   3   N06W29 0007   BXO  
11891 2013.11.05
2013.11.06
      S17W65        

plage

11892 2013.11.06   3 2 S05E09 0010   BXO location: S07E12
S2813 2013.11.06       N18W38           plage
11894 2013.11.07
2013.11.08
      S06W61         plage
11893 2013.11.07
2013.11.08
5 6 4 S12E42 0180 CSO DAO area: 0240
S2816 2013.11.07   1   S26W17 0002   AXX  
S2818 2013.11.07       N25W35           plage
S2819 2013.11.08   3 1 S27E26 0025   CRO  
S2820 2013.11.08       N21W07           plage
S2821 2013.11.08       N10W09           plage
11895 2013.11.09
2013.11.10
4 13 7 S15E67 0060 CAO FKC area: 0700

location: S18E75

S2823 2013.11.09       N07W15         plage
11896 2013.11.10 1 1 1 N13E75 0110 HSX HHX    
S2826 2013.11.10   4 3 S25E10 0017   BXO    
Total spot count: 40 110 49  
Sunspot number: 90 210 119  (total spot count + 10 * number of spotted regions)
Weighted SN: 65 148 87  (Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10)
Relative sunspot number (Wolf number): 54 74 65 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for STAR SDO 2K, k = 0.55 for STAR SDO 1K

Monthly solar cycle data

Month Average measured solar flux International sunspot number (SIDC) Smoothed sunspot number Average ap
(3)
2011.11 153.5 (cycle peak) 96.7 (cycle peak) 61.1 (+1.2) 5.55
2012.02 106.5 32.9 66.9 (+1.4)
likely cycle 24 max
8.81
2012.07 133.9 66.5 57.8 (-1.1) 13.90
2012.08 115.4 63.0 58.2 (+0.4) 7.96
2012.09 122.9 61.4 58.1 (-0.1) 8.07
2012.10 123.3 53.3 58.6 (+0.5) 9.97
2012.11 121.3 61.8 59.7 (+1.1) 7.08
2012.12 108.6 40.8 59.6 (-0.1) 3.44
2013.01 127.1 62.9 58.7 (-0.9) 4.69
2013.02 104.3 38.0 58.4 (-0.3) 6.11
2013.03 111.3 57.9 57.5 (-0.9) 10.56
2013.04 124.8 72.4 57.9 (+0.4) 5.40
2013.05 131.4 78.7 (59.3 projected, +1.4) 9.73
2013.06 110.1 52.5 (59.7 projected, +0.4) 12.60
2013.07 115.5 57.0 (60.0 projected, +0.3) 9.47
2013.08 114.6 66.0 (60.3 projected, +0.3) 8.27
2013.09 102.6 36.9 (60.2 projected, -0.1) 5.23
2013.10  132.1 85.6 (58.7 projected, -1.5) 7.71
2013.11  147.6 (1) 43.2 (2A) / 129.7 (2B) / 87.8 (2C) (56.6 projected, -2.1) (6.8)

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) Boulder SN current month average to date. 2C) STAR SDO 1K Wolf number 30 day average.
3) Running average based on the quicklook and definitive Potsdam WDC ap indices. Values in red are based on the definitive international Potsdam WDC ap indices.

This report has been prepared by Jan Alvestad. It is based on the 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.