Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 9, 2013 at 05:00 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 quiet to unsettled on November 8. Solar wind speed at SOHO ranged between 349 and 438 km/s. A disturbance began early on November 9, likely related to the arrival of the CME observed on Nov.5.

Solar flux measured at 20h UTC on 2.8 GHz was 146.0 (increasing 18.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 121.2. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.5). Three hour interval K indices: 31110000 (planetary), 21211211 (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 13 active regions in 2K resolution (SN: 301) and 9 active regions in 1K resolution (SN: 171) SDO images on the visible solar disk.

Region 11887 [N19W60] was quiet and stable.
Region 11890 [S10W02] decayed significantly losing spots and penumbral area. There is still a persistent magnetic delta structure in a southeastern penumbra. Further M and X class flares are possible.
C5+ flares: major impulsive X1.1/2B at 04:26 UTC. This event was associated with a full halo CME where most of the ejecta was observed off the southern limbs.
Region 11891 [S18W37] was active during the first half of the day, then began to decay. The magnetic delta disappeared with only minor polarity intermixing remaining. C5+ flares: C5.7 at 02:40, M2.3/1B at 09:29 UTC.
Region 11892 [S05E38] decayed slowly and quietly.
New region 11893 [S13E67] rotated into view on November 7 and was numbered the next day by SWPC.
New region 11894 [S07W32] emerged on November 7 and got its NOAA number the next day.

Spotted regions not numbered by SWPC:
S2796 [N07W35] was quiet and stable.
S2803 [N05W03] was quiet and stable.
S2816 [S22E18] was quiet and stable.
S2818 [N25W09] was quiet and stable.
New region S2819 [S27E51] emerged with a penumbra spot.
New region S2820 [N21E19] emerged with penumbra spots.
New region S2821 [N10E17] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

November 6-7: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
November 8: A full halo CME was observed after the X1 event in AR 11890 early in the day. The CME could reach Earth on November 10.

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 recurrent trans equatorial coronal hole (CH593) was in an Earth facing position on November 7-8.

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 fair to good.

Forecast

The geomagnetic field is expected to be unsettled to minor storm on November 9 due to CME effects, isolated major storm intervals are possible. On November 10-11 effects from CH593 and the CME observed after the X1 event on Nov.8 could cause unsettled to major storm conditions.

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
11887 2013.10.29
2013.10.30
9 12 7 N19W59 0080 CAO CRO

 

S2792 2013.10.30       S10W45           plage
S2796 2013.10.31   4 1 N07W35 0009   BXO  
11890 2013.11.01
2013.11.02
58 106 55 S11W02 0920 EHC EHC beta-gamma-delta

area: 0800

11889 2013.11.02 2     S19W58 0010 BXO     spotless
S2800 2013.11.02       S08W19           plage
S2803 2013.11.03   4   N05W03 0007   BXO  
11891 2013.11.05
2013.11.06
17 22 12 S18W37 0120 DAI DAI

area: 0090

S2810 2013.11.05       N01W45           plage
11892 2013.11.06 1 2 1 S05E39 0000 AXX AXX area: 0010
S2813 2013.11.06       N18W12           plage
11894 2013.11.07
2013.11.08
2 3 3 S07W34 0010 BXO CRO area: 0021
11893 2013.11.07
2013.11.08
1 2 1 S12E66 0130 HSX CAO  
S2816 2013.11.07   5   S22E18 0009   BXO  
S2818 2013.11.07   7   N25W09 0015   BXO  
S2819 2013.11.08   1   S27E51 0002   AXX    
S2820 2013.11.08   2 1 N21E19 0007   BXO    
S2821 2013.11.08   1 1 N10E17 0005   AXX    
Total spot count: 90 171 82  
Sunspot number: 160 301 172  (total spot count + 10 * number of spotted regions)
Weighted SN: 115 197 108  (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): 96 105 95 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)
likely 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) 7.65
2013.11  146.8 (1) 37.1 (2A) / 139.0 (2B) / 88.5 (2C) (56.6 projected, -2.1) (4.9)

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.