Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 12, 2013 at 05:05 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 11. Solar wind speed at SOHO ranged between 429 and 598 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 163.7 (increasing 38.4 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 122.3. The Potsdam WDC planetary A index was 15 (STAR Ap - based on the mean of three hour interval ap indices: 15.4). Three hour interval K indices: 44433321 (planetary), 44442321 (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 7 active regions in 2K resolution (SN: 169) and 5 active regions in 1K resolution (SN: 100) SDO images on the visible solar disk.

Region 11890 [S11W42] decayed further but could still produce another major flare due to the persistent magnetic delta structure in a trailing penumbra. C5+ flares: C6.4 at 00:32, C7.8 at 00:48, C5.0 at 17:01 UTC.
Region 11892 [S07W03] was quiet and stable.
Region 11893 [S13E29] developed slowly and has polarity intermixing. C and minor M class flaring is possible.
Region 11895 [S19E62] is a large region with many spots and polarity intermixing. Further M class flares are possible.
C5+ flare: M2.4 at 11:18 UTC.
Region 11896 [N10E62] was quiet and stable.
New region 11898 [S27E12] emerged on November 8 and was numbered by SWPC 3 days later.

Spotted regions not numbered by SWPC:
S2803 [N05W39] was quiet and stable.

Active regions at the northeast limb will rotate into view today. The regions are contributing to a significant increase in solar flux. Major flares are possible.

Coronal mass ejections (CMEs)

November 9, 11: 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 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.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 12-14. 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
S2796 2013.10.31       N05W79         plage
11890 2013.11.01
2013.11.02
29 44 24 S11W42 0410 EKC EKC beta-gamma-delta
S2800 2013.11.02       S08W58           plage
S2803 2013.11.03   1   N05W39 0003   AXX  
11891 2013.11.05
2013.11.06
      S17W79          

plage

11892 2013.11.06   2   S05W06 0010   AXX location: S07W03
S2813 2013.11.06       N18W51           plage
11894 2013.11.07
2013.11.08
      S06W76           plage
11893 2013.11.07
2013.11.08
4 9 7 S12E28 0170 DSO DHC beta-gamma

area: 0330

S2816 2013.11.07       S26W30         plage
S2818 2013.11.07       N25W48           plage
11898 2013.11.08
2013.11.11
1 2 1 S26E11 0010 AXX HRX area: 0023
S2820 2013.11.08       N21W20           plage
S2821 2013.11.08       N10W22           plage
11895 2013.11.09
2013.11.10
2 40 17 S15E52 0090 CAO FKC beta-gamma

area: 0800

location: S19E62

S2823 2013.11.09       N07W28           plage
11896 2013.11.10 1 1 1 N11E60 0140 HSX HHX location: N10E62

area: 0320

S2826 2013.11.10       S25W03         plage
11897 2013.11.11 7     S18E64 0240 DAI       magnetically part of 11895
Total spot count: 44 99 50  
Sunspot number: 104 169 100  (total spot count + 10 * number of spotted regions)
Weighted SN: 74 142 93  (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): 62 59 55 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  149.1 (1) 46.7 (2A) / 127.4 (2B) / 87.1 (2C) (56.6 projected, -2.1) (7.6)

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.