Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 13, 2013 at 03:55 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 very quiet on November 12. Solar wind speed at SOHO ranged between 389 and 526 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 167.5 (increasing 39.4 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 122.7. The Potsdam WDC planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 2.4). Three hour interval K indices: 11000010 (planetary), 11002200 (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 11 active regions in 2K resolution (SN: 237) and 9 active regions in 1K resolution (SN: 149) SDO images on the visible solar disk.

Region 11890 [S12W58] decayed slowly and was mostly quiet. The trailing magnetic delta structure is disintegrating. There's still a chance of an M class flare.
Region 11893 [S14E17] was mostly quiet and stable.
Region 11895 [S20E49] was the most active region on the visible disk. Centrally there's a weak magnetic delta structure. Decay was observed in the trailing spot section. M class flares are possible.
C5+ flare: C9.8 long duration event peaking at 23:08 UTC.
Region 11896 [N10E48] was quiet and stable.
Region 11898 [S27E01] gained trailing spots and was quiet.
New region 11899 [N05E76] rotated into view with a large penumbra and a weak magnetic delta structure in the northeastern part. Major flares are possible.

Spotted regions not numbered by SWPC:
S2803 [N07W53] was quiet and stable.
S2816 [S19W27] reemerged with penumbra spots.
S2826 [S25W16] reemerged with penumbra spots.
New region S2828 [S15E65] emerged to the east of AR 11895.
New region S2829 [S20E12] emerged with a few spots.

Coronal mass ejections (CMEs)

November 11-12: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
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.

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 coronal hole (CH594) in the northern hemisphere will 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 poor.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 13-14. A high speed stream from CH594 could reach Earth on November 15 and cause unsettled and active intervals.

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
11890 2013.11.01
2013.11.02
32 33 10 S11W55 0420 EKC EKC beta-gamma-delta
S2803 2013.11.03   1   N07W53 0001   AXX  
11892 2013.11.06       S05W21         plage
11893 2013.11.07
2013.11.08
8 11 5 S13E15 0240 DSO DSO

area: 0290

S2816 2013.11.07   2   S19W27 0003   AXX    
11898 2013.11.08
2013.11.11
2 7 4 S26W00 0020 CRO CRO  
S2820 2013.11.08       N21W33           plage
S2821 2013.11.08       N10W35           plage
11895 2013.11.09
2013.11.10
7 55 29 S16E37 0090 CSO FKC beta-gamma-delta

area: 0800

location: S19E62

includes AR 11897

S2823 2013.11.09       N07W41           plage
11896 2013.11.10 1 1 1 N11E46 0190 HSX HHX location: N10E48

area: 0320

S2826 2013.11.10   4 2 S25W16 0013   BXO    
11897 2013.11.11 26     S20E51 0600 EKC       magnetically part of 11895
11899 2013.11.12 1 3 3 N06E76 0250 HHX DKC   beta-delta

area: 0770

S2828 2013.11.12   4 2 S15E65 0016   BXO    
S2829 2013.11.12   6 3 S20E12 0020   CRO    
Total spot count: 77 127 59  
Sunspot number: 147 237 149  (total spot count + 10 * number of spotted regions)
Weighted SN: 125 178 110  (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): 88 83 82 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  150.7 (1) 51.6 (2A) / 129.0 (2B) / 87.1 (2C) (56.6 projected, -2.1) (7.2)

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.