Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 16, 2013 at 06:05 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 unsettled on November 15. Solar wind speed at SOHO ranged between 323 and 356 km/s. Wind density increased slowly after noon and peaked just before midnight indicating the arrival of a weak stream from CH594.

Solar flux measured at 20h UTC on 2.8 GHz was 177.9 (increasing 45.2 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 124.0. The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 7.9). Three hour interval K indices: 22111233 (planetary), 12122324 (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 11 active regions in 2K resolution (SN: 379) and 9 active regions in 1K resolution (SN: 208) SDO images on the visible solar disk.

Region 11893 [S13W23] developed slowly and could produce C and minor M class flares.
Region 11895 [S18E07] developed in the leading section while slow decay was observed in the trailing spot section. There is a weak magnetic delta structure in a central penumbra. M class flares are possible.
C5+ flares: C7.5/1N at 11:35 UTC.
Region 11896 [N10E09] was quiet and stable.
Region 11898 [S27W37] was quiet and stable.
Region 11899 [N05E36] was mostly unchanged apart from a new umbra emerging in the northwestern part of the main penumbra. There is polarity intermixing and a chance of a major flare.
C5+ flares: M1.0 at 02:29 UTC.
Region 11900 [S20W27] decayed slightly and was mostly quiet.
Region 11901 [S24W57] developed slowly and quietly.
New region 11902 [N19W05] emerged on November 13 and was numbered by SWPC 2 days later.

Spotted regions not numbered by SWPC:
S2828 [S16E26] was quiet and stable.
S2834 [N10E27] developed slowly and quietly.
New region S2836 [N07W51] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

November 13-15: 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

A coronal hole (CH594) in the northern hemisphere was in 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 poor to fair.

Forecast

The geomagnetic field is expected to be quiet to active on November 16 due to effects from CH594. Quiet conditions are likely on November 17-18.

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
11890 2013.11.01
2013.11.02
3     S13W95 0010 AXX AXX   rotated out of view
11892 2013.11.06       S05W66           plage
11893 2013.11.07
2013.11.08
24 41 20 S13W25 0240 DSC DKC

beta-gamma

area: 0400

11898 2013.11.08
2013.11.11
4 3 1 S26W37 0010 BXO BXO  
11895 2013.11.09
2013.11.10
3 110 51 S16W02 0100 HSX FAC beta-gamma-delta

area: 0500

location: S18E07

includes AR 11897

11896 2013.11.10 2 11 5 N11E07 0130 HAX CSO location: N10E09

area: 0250

11901 2013.11.10
2013.11.14
8 13 5 S24W57 0020 CRO DAO area: 0070
11897 2013.11.11 84     S21E12 0360 EKC       magnetically part of 11895
11899 2013.11.12 14 33 14 N06E35 0600 DKO DKO

area: 0900

S2828 2013.11.12   6   S16E26 0010   BXO  
11900 2013.11.12
2013.11.14
24 34 14 S19W29 0150 DAC DAC beta-gamma-delta
11902 2013.11.13
2013.11.14
6 14 6 N19W06 0020 DSO DRO  
S2831 2013.11.13       N18W48         plage
S2832 2013.11.14       S30W20         plage
S2833 2013.11.14       S10W53         plage
S2834 2013.11.14   3 2 N10E27 0010   BXO  
S2835 2013.11.14       N01E20         plage
S2836 2013.11.15   1   N07W51 0002   AXX    
Total spot count: 172 269 118  
Sunspot number: 272 379 208  (total spot count + 10 * number of spotted regions)
Weighted SN: 220 312 151  (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): 163 133 114 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  155.5 (1) 72.7 (2A) / 145.5 (2B) / 90.1 (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.