Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 20, 2013 at 06:00 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 19. Solar wind speed at SOHO ranged between 349 and 441 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 152.9 (increasing 0.2 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 125.3. The Potsdam WDC planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 2.6). Three hour interval K indices: 00010111 (planetary), 00002211 (Boulder).

The background x-ray flux was at the class B6 level.

At the time of counting spots (see image time) spots were observed in 9 active regions in 2K resolution (SN: 183) and 8 active regions in 1K resolution (SN: 108) SDO images on the visible solar disk.

Region 11893 [S13W77] produced the only interesting flare of the day and could produce another major flare while rotating around the southwest limb. The region still has a magnetic delta structure in the largest penumbra. C5+ flare: major X1.0 at 10:26 UTC. The flare was associated with a CME where most of the ejected material was observed off the southwest limb.
Region 11895 [S17W49] decayed slowly.
Region 11896 [N10W44] was quiet and stable.
Region 11899 [N05W17] was quiet and stable. There's a small chance of a major flare.
Region 11900 [S22W77] decayed slowly and quietly.
Region 11903 [S11E49] was quiet and stable.

Spotted regions not numbered by SWPC:
S2837 [N13E45] was quiet and stable.
S2839 [S15E03] was quiet and stable.
S2843
[N08E18] was quiet and stable.

Coronal mass ejections (CMEs)

November 17-18: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
November 19: A halo CME was observed after the X1 event in AR 11893. Most of the ejecta was observed off the southwest limb and the south pole. Faint extensions were observed elsewhere.

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 an Earth facing position.

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 20-22.

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
11893 2013.11.07
2013.11.08
14 10 5 S13W77 0430 EKC DKC

 

11895 2013.11.09
2013.11.10
1 25 8 S17W55 0040 HSX CSO

location: S17W49

includes AR 11897

11896 2013.11.10 1 3 1 N12W46 0160 HSX CSO

 

11897 2013.11.11 10     S18W41 0070 FSO       magnetically part of 11895
11899 2013.11.12 8 32 8 N05W16 0610 CKO CHO

area: 0850

S2828 2013.11.12       S16W26           plage
11900 2013.11.12
2013.11.14
7 4 2 S21W79 0100 DAI HRX  
11902 2013.11.13
2013.11.14
      N20W61         plage
S2834 2013.11.14       N09W25          
S2835 2013.11.14       N01W07           plage
S2837 2013.11.16   5   N14E45 0010   BXO  
S2838 2013.11.16       S11W27           plage
S2839 2013.11.16   11 1 S15E03 0030   BXO images\AR_S2839_20131119_2345.png  
11903 2013.11.17 2 2 2 S10E48 0130 HAX HSX area: 0240
S2843 2013.11.17   1 1 N08E18 0005   AXX  
S2844 2013.11.18       S04E08         plage
S2845 2013.11.18       S33E68         plage
S2846 2013.11.18       S23E32         plage
Total spot count: 43 93 28  
Sunspot number: 113 183 108  (total spot count + 10 * number of spotted regions)
Weighted SN: 88 131 66  (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): 68 64 59 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  157.9 (1) 97.8 (2A) / 154.4 (2B) / 92.1 (2C) (56.6 projected, -2.1) (6.6)

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.