Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 18, 2013 at 05:25 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 November 17. Solar wind speed at SOHO ranged between 426 and 593 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 177.0 (increasing 41.2 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 124.9. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.1). Three hour interval K indices: 22221011 (planetary), 22332211 (Boulder).

The background x-ray flux was at the class B8 level.

At the time of counting spots (see image time) spots were observed in 13 active regions in 2K resolution (SN: 329) and 12 active regions in 1K resolution (SN: 220) SDO images on the visible solar disk.

Region 11893 [S12W50] still has a magnetic delta structure in the largest penumbra. A major flare is possible.
Region 11895 [S19W17] decayed after noon and has no large spots. The region produced a few low level C flares and could be capable of minor M class flaring due to polarity intermixing.
Region 11896 [N10W18] was quiet and stable.
Region 11899 [N05E09] lost small spots after noon. Other than the large penumbra the region currently has little magnetic complexity. A major flare is still possible.
Region 11900 [S20W52] decayed significantly losing the magnetic delta structures.
C5+ flares: M1.0 at 05:10 UTC.
Region 11902 [N20W32] decayed slowly and quietly.
New region 11903 [S11E76] rotated into view.

Spotted regions not numbered by SWPC:
S2834 [N09E01] decayed slowly and quietly.
S2837 [N13E69] was quiet and stable.
S2838 [S11W02] was quiet and stable.
S2839 [S12E25] was quiet and stable.
New region S2842 [N15W23] emerged with a penumbra spot.
New region S2843 [N11E42] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

November 15-17: 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 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 18-20.

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
31 41 18 S13W52 0420 DKC DKC

beta-gamma-delta

area: 0600

11898 2013.11.08
2013.11.11
      S26W65           plage
11895 2013.11.09
2013.11.10
5 76 42 S16W30 0080 HSX FSI beta-gamma

area: 0300

location: S19W17

includes AR 11897

11896 2013.11.10 6 8 5 N11W19 0150 CAO CSO

area: 0210

11901 2013.11.10
2013.11.14
3     S24W82 0030 CRO     spotless
11897 2013.11.11 94     S20W15 0240 FAC       magnetically part of 11895
11899 2013.11.12 18 23 11 N06E10 0510 CKO CKO

beta-gamma

area: 0850

S2828 2013.11.12       S16W00           plage
11900 2013.11.12
2013.11.14
31 30 14 S19W55 0130 DAC DAI beta-gamma

location: S21W52

11902 2013.11.13
2013.11.14
3 4 2 N20W32 0020 CSO BXO  
S2832 2013.11.14       S30W46           plage
S2834 2013.11.14   4 2 N09E01 0012   BXO  
S2835 2013.11.14       N01W07           plage
S2837 2013.11.16   3 1 N13E69 0014   BXO  
S2838 2013.11.16   2   S11W02 0003   BXO  
S2839 2013.11.16   4 1 S12E25 0011   AXX  
S2840 2013.11.16       S29W45         plage
11903 2013.11.17 1 2 2 S12E77 0060 HSX HSX   area: 0210
S2842 2013.11.17   1 1 N15W23 0005   AXX    
S2843 2013.11.17   1 1 N11E42 0004   AXX    
Total spot count: 192 199 100  
Sunspot number: 282 329 220  (total spot count + 10 * number of spotted regions)
Weighted SN: 245 239 140  (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): 169 115 121 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) 89.2 (2A) / 157.5 (2B) / 92.0 (2C) (56.6 projected, -2.1) (7.1)

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.