Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 25, 2013 at 04:10 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 inactive on November 24. Solar wind speed at SOHO ranged between 284 and 360 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 127.1 (decreasing 32.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 126.1. The Potsdam WDC planetary A index was 1 (STAR Ap - based on the mean of three hour interval ap indices: 1.0). Three hour interval K indices: 00000000 (planetary), 00011110 (Boulder).

The background x-ray flux was at the class B4 level.

At the time of counting spots (see image time) spots were observed in 9 active regions in 2K resolution (SN: 129) and 7 active regions in 1K resolution (SN: 90) SDO images on the visible solar disk.

Region 11899 [N06W85] was quiet and stable.
Region 11903 [S11W16] was quiet and stable.
Region 11904 [N11W79] rotated partly out of view and produced several small C flares.

Region 11905 [N19E60] gained penumbral area and was mostly quiet.

Spotted regions not numbered by SWPC:
S2837 [N14W21] was quiet and stable.
S2852 [S08E41] was quiet and stable.
S2855 [S31W08] decayed slowly and quietly.
S2856 [S16E56] wa squiet and stable.
New region S2857 [N01E35] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

November 22-24: 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

No obvious coronal holes are currently in or near Earth facing positions.

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 to fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on Nov.24-26.

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
11899 2013.11.12 4 1 1 N07W84 0560 HHX HHX

area: 0850

S2837 2013.11.16   8 4 N14W21 0020   BXO  
S2839 2013.11.16       S19W45          
11903 2013.11.17 2 8 4 S12W19 0110 HAX CAO area: 0200
S2843 2013.11.17       N11W48           plage
S2844 2013.11.18       S04W31           plage
S2845 2013.11.18       S33E03           plage
S2846 2013.11.18       S23W33           plage
11904 2013.11.19
2013.11.23
12 1 1 N12W82 0130 DAI HAX

 

S2851 2013.11.21       S10W30           plage
S2852 2013.11.22   2   S08E41 0004   AXX  
11905 2013.11.22
2013.11.23
11 13 8 N18E57 0060 DSO DAI location: N19E60

area: 0110

S2855 2013.11.22   2 1 S31W08 0012   AXX  
S2856 2013.11.23   3 1 S16E56 0020   HRX  
S2857 2013.11.24   1   N01E35 0002   AXX    
Total spot count: 29 39 20  
Sunspot number: 69 129 90  (total spot count + 10 * number of spotted regions)
Weighted SN: 54 67 48  (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): 41 45 50 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  153.9 (1) 110.0 (2A) / 137.5 (2B) / 86.2 (2C) (56.6 projected, -2.1) (6.3)

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.