Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 14, 2013 at 05:55 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 13. Solar wind speed at SOHO ranged between 349 and 450 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 171.0 (increasing 34.9 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 123.2. The Potsdam WDC planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 2.9). Three hour interval K indices: 01111010 (planetary), 01122211 (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 12 active regions in 2K resolution (SN: 308) and 12 active regions in 1K resolution (SN: 203) SDO images on the visible solar disk.

Region 11890 [S11W71] decayed slowly and produced a few C flares. C5+ flare: C6.5 at 03:51 UTC.
Region 11893 [S13E03] developed slowly and could produce C and minor M class flares.
Region 11895 [S20E35] has many spots, significant polarity intermixing and currently no magnetic delta structures. Further M class flares are possible.
C5+ flares: M1.4 at 15:20, C5.9 at 20:42 UTC.
Region 11896 [N10E35] was quiet and stable.
Region 11898 [S27W11] was quiet and stable.
Region 11899 [N05E64] has a large main penumbra and only a few small spots. Occasional M class flares are possible.

Spotted regions not numbered by SWPC:
S2816 [S19W40] was quiet and stable.
S2826 [S23W30] developed slowly and quietly.
S2828 [S15E50] was quiet and stable.
S2829 [S19W02] developed slowly and quietly.
New region S2830 [N18E20] emerged with penumbra spots in an old plage area.
New region S2831 [N18W21] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

November 11-13: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.

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 was in 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 to fair.

Forecast

The geomagnetic field is expected to be quiet on November 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
13 17 6 S11W69 0290 EKC CAO beta-gamma

location: S11W71

S2803 2013.11.03       N07W66         plage
11892 2013.11.06       S05W34           plage
11893 2013.11.07
2013.11.08
6 27 13 S12E03 0140 DSO DHC

beta-gamma

area: 0360

S2816 2013.11.07   2 1 S19W40 0005   AXX  
11898 2013.11.08
2013.11.11
3 8 5 S26W14 0010 BXO CRO area: 0030

location: S27W11

S2820 2013.11.08       N21W46           plage
S2821 2013.11.08       N10W48           plage
11895 2013.11.09
2013.11.10
3 98 38 S15E24 0120 HSX FSC beta-gamma

area: 0700

location: S20E35

includes AR 11897

S2823 2013.11.09       N07W54           plage
11896 2013.11.10 1 3 2 N12E34 0140 HAX CKO location: N10E35

area: 0320

S2826 2013.11.10   6 3 S24W30 0022   CRO  
11897 2013.11.11 29     S21E37 0610 EKC       magnetically part of 11895
11899 2013.11.12 3 9 6 N06E62 0360 HKX CKO

area: 0850

S2828 2013.11.12   1 1 S15E50 0010   HRX  
S2829 2013.11.12   10 6 S19W02 0050   DRO  
S2830 2013.11.13   6 1 N18E20 0016   BXO    
S2831 2013.11.13   1 1 N18W21 0006   AXX    
Total spot count: 58 188 83  
Sunspot number: 128 308 203  (total spot count + 10 * number of spotted regions)
Weighted SN: 103 240 125  (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): 77 108 112 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  152.2 (1) 55.9 (2A) / 128.9 (2B) / 88.0 (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.