Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 23, 2013 at 05:10 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 very quiet on November 22. Solar wind speed at SOHO ranged between 274 and 365 km/s. On Nov.23 after 00:37 UT at SOHO solar wind speed and density increased, possibly the arrival of the CME observed on November 19.

Solar flux measured at 20h UTC on 2.8 GHz was 142.8 (decreasing 17.4 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 125.8. The Potsdam WDC planetary A index was 1 (STAR Ap - based on the mean of three hour interval ap indices: 1.4). Three hour interval K indices: 10000011 (planetary), 00000111 (Boulder).

The background x-ray flux was at the class B7 level.

At the time of counting spots (see image time) spots were observed in 11 active regions in 2K resolution (SN: 174) and 11 active regions in 1K resolution (SN: 143) SDO images on the visible solar disk.

Region 11896 [N10W84] was quiet and stable.
Region 11899 [N06W58] was quiet and stable.
Region 11903 [S11E10] was quiet and stable.

Spotted regions not numbered by SWPC:
S2837 [N15E08] reemerged with penumbra spots.
S2838 [S11W70] developed slowly and quietly.
S2839 [S13W22] was quiet and stable.
S2847
[N12W57] merged with AR S2849. The region produced an M1.1 flare at 02:29 UTC on Nov.23.
S2851 [S10W04] was quiet and stable.
New region S2852 [S10E69] rotated into view.
New region S2854 [N19E82] rotated into view.
New region S2855 [S30E15] emerged with two spots.

Coronal mass ejections (CMEs)

November 20-22: 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. Propagation on long distance northeast-southwest paths is poor to fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on Nov.23 due to CME effects. Quiet conditions are likely on Nov.24-25. on November 22-24.

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
11896 2013.11.10 1 1 1 N10W84 0050 HSX HSX

 

11897 2013.11.11 1     S17W84 0030 CRO       magnetically part of 11895

rotated out of view

CRO classification not possible with 1 spot

11899 2013.11.12 8 4 2 N07W56 0560 DKO CKO

area: 0850

location: N06W58

S2835 2013.11.14       N01W48           plage
S2837 2013.11.16   5 2 N15E08 0012   BXO    
S2838 2013.11.16   5 2 S11W70 0035   DRO  
S2839 2013.11.16   9 2 S13W22 0025   BXO images/AR_S2839_20131122_2345.png images/AR_S2839_20131121_2345.png  
11903 2013.11.17 1 7 3 S14E08 0100 HSX CSO area: 0230
S2843 2013.11.17       N11W22         plage
S2844 2013.11.18       S04W05           plage
S2845 2013.11.18       S33E29           plage
S2846 2013.11.18       S23W07           plage
S2847 2013.11.19   23 13 N12W57 0100   DRI beta-gamma
S2849 2013.11.21       N14W52         merged with AR S2847
S2850 2013.11.21       S08W82         plage
S2851 2013.11.21   3 2 S10W04 0009   BXO  
S2852 2013.11.22   2 2 S10E69 0012   CRO    
S2854 2013.11.22   3 2 N19E82 0025   DRO    
S2855 2013.11.22   2 2 S30E15 0020   CRO    
Total spot count: 11 64 33  
Sunspot number: 51 174 143  (total spot count + 10 * number of spotted regions)
Weighted SN: 34 99 68  (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): 31 61 79 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  156.0 (1) 105.5 (2A) / 143.8 (2B) / 88.8 (2C) (56.6 projected, -2.1) (6.0)

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.