Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 17, 2013 at 06:10 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 active on November 16. Solar wind speed at SOHO ranged between 317 and 600 km/s under the influence of a high speed stream from CH594.

Solar flux measured at 20h UTC on 2.8 GHz was 174.5 (increasing 41.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 124.4. The Potsdam WDC planetary A index was 14 (STAR Ap - based on the mean of three hour interval ap indices: 13.8). Three hour interval K indices: 44333112 (planetary), 22233322 (Boulder).

The background x-ray flux was at the class C1 level.

At the time of counting spots (see image time) spots were observed in 12 active regions in 2K resolution (SN: 435) and 11 active regions in 1K resolution (SN: 265) SDO images on the visible solar disk.

Region 11893 [S12W38] developed further and could produce a major flare.
Region 11895 [S19W04] was mostly quiet. The region has many small spots and no large penumbrae. Due to significant polarity intermixing there is a chance of M class flaring.
Region 11896 [N10W04] was quiet and stable.
Region 11899 [N05E23] has a small and slowly developing magnetic delta structure in the northwestern part of the large penumbra. A major flare is possible.
Region 11900 [S20W40] developed and has two magnetic delta structures. The region was very active and produced many C flares and 2 M flares.
C5+ flares: M1.2 at 04:53, M1.6/1F at 07:49, C5.2 at 23:31 UTC.
Region 11901 [S23W71] decayed slowly and quietly.
Region 11902 [N19W19] decayed slowly and quietly.

Spotted regions not numbered by SWPC:
S2834 [N09E14] developed slowly and quietly.
New region S2837 [N14E81] rotated partly into view. The region could be capable of producing a minor M class flare. C5+ flares: C5.2 at 02:42, C8.6 at 06:21 (wrongly attributed to AR 11897 by SWPC) UTC.
New region S2838 [S12E13] emerged with penumbra spots.
New region S2839 [S19E36] emerged with penumbra spots in an old plage area.
New region S2840 [S29W32] emerged with a few spots.

Coronal mass ejections (CMEs)

November 14-16: 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 fair.

Forecast

The geomagnetic field is expected to be quiet on November 17-19.

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
11892 2013.11.06       S05W81           plage
11893 2013.11.07
2013.11.08
23 55 33 S13W39 0290 DKC DKC

beta-gamma-delta

area: 0520

11898 2013.11.08
2013.11.11
      S26W51         plage
11895 2013.11.09
2013.11.10
2 129 63 S16W17 0070 HAX FSC beta-gamma

area: 0400

location: S19W04

includes AR 11897

11896 2013.11.10 3 15 7 N11W06 0150 HSX CSO location: N10W04

area: 0230

11901 2013.11.10
2013.11.14
7 4 3 S24W70 0030 CRO CRO  
11897 2013.11.11 63     S20W04 0240 FAC       magnetically part of 11895
11899 2013.11.12 11 40 15 N06E23 0510 DKO DKO

beta-gamma-delta

area: 0900

S2828 2013.11.12       S16E13         plage
11900 2013.11.12
2013.11.14
20 44 21 S19W42 0110 DAC DAC beta-gamma-delta

location: S20W40

11902 2013.11.13
2013.11.14
4 7 5 N20W20 0050 DSO CRO area: 0030
S2832 2013.11.14       S30W33           plage
S2834 2013.11.14   9 4 N09E14 0040   DRO  
S2835 2013.11.14       N01E07           plage
S2837 2013.11.16   2   N14E81 0005   BXO    
S2838 2013.11.16   2 2 S12E13 0008   BXO    
S2839 2013.11.16   3 1 S19E36 0007   AXX    
S2840 2013.11.16   5 1 S29W32 0025   CRO    
Total spot count: 133 315 155  
Sunspot number: 213 435 265  (total spot count + 10 * number of spotted regions)
Weighted SN: 181 362 202  (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): 128 152 146 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)
possibe 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  156.7 (1) 79.8 (2A) / 149.7 (2B) / 91.7 (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.