Solar Terrestrial Activity Report

Activity chart

Last major update issued on November 29, 2015 at 05:50 UT.

Charts (* = updated daily) Data and archive
  Solar wind (*) Solar and geomagnetic data - last month (*)
  Electron fluence (*) Archived daily reports and monthly data from 2003.01 (November 1, 2015)
Solar cycle Solar cycles 23-24 (November 1, 2015) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24 progress (November 1, 2015) Noon SDO sunspot count 1K Reference: 4K (large file) (*)
  Solar cycles 1-24 (July 17, 2015) POES auroral activity level October 2009 - December 2012
  Comparison of cycles 21, 22, 23 and 24 (November 1, 2015) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12, 13, 14, 16 and 24 (November 1, 2015) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (November 16, 2015)  

Recent activity

The geomagnetic field was quiet to unsettled on November 28 under the influence of a weak disturbance (maybe associated with CH702). Solar wind speed at SOHO ranged between 290 and 415 km/s. Solar wind speed increased slowly during the latter half of the day. ACE data early on November 29 indicate that a low speed coronal hole stream is currently the dominant solar wind source. The Bz component of the IMF has been mostly northwards resulting in only a weak disturbance.

Solar flux at 20h UTC on 2.8 GHz was 96.6 (decreasing 27.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 104.5. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.3). Three hour interval K indices: 11122123 (planetary), 01223222 (Boulder).

The background x-ray flux is at the class B1 level.

At the time of counting spots (see image time), spots were observed in 8 active regions using 2K resolution (SN: 140) and 6 active regions using 1K resolution (SN: 90) SDO images on the visible solar disk.

Region 12457 [N11W39] decayed slowly and quietly.
Region 12458 [N08W09] was quiet and stable.
Region 12459 [N04E22] gained tiny spots and was quiet.
Region 12460 [N11W13] decayed slowly and quietly.

Spotted regions not numbered (or interpreted differently) by SWPC:
New region S4926 [S07W39] emerged early in the day with tiny spots.
New region S4927 [S21E12] was observed with a tiny spot.
New region S4928 [N19W48] emerged with tiny spots.
New region S4929 [N11W58] emerged with tiny spots.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
           

Flare activity (SDO/EVE/ESP XRS-B proxy)

Coronal mass ejections (CMEs)

November 26-28: No obviously Earth directed CMEs were observed in available LASCO 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 recurrent southern hemisphere coronal hole (CH703) will rotate into an Earth facing position on November 27-28.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over 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 November 29 with a chance of active intervals. Quiet to active conditions are likely on November 30 and December 1, maybe with minor storm intervals, due to effects from CH703.

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: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% 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 overlays
Comment
SWPC Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12457 2015.11.18
2015.11.19
1 8 4 N12W40 0020 HAX CAO

area: 0040

S4912 2015.11.20       N20W26          
12458 2015.11.21
2015.11.22
4 22 14 N08W07 0080 CAO CAI

area: 0140

location: N08W09

12459 2015.11.24 1 20 8 N04E19 0010 AXX CRO  
12460 2015.11.24
2015.11.25
  2 1 N12W15 0006   BXO  
S4922 2015.11.25       S04W24            
S4923 2015.11.25       S18W24            
S4926 2015.11.28   3 2 S07W39 0010   BXO    
S4927 2015.11.28   1   S21E12 0002   AXX    
S4928 2015.11.28   2   N19W48 0002   BXO    
S4929 2015.11.28   2 1 N11W58 0006   BXO    
Total spot count: 6 60 30  
Sunspot number: 36 140 90  (total spot count + 10 * number of spotted regions)
Weighted SN: 16 73 43  (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): 40 77 77 k * (sunspot number)
As of July 1, 2015: k = 1.1 for SWPC, k = 0.55 for MSN 2K, k = 0.85 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO) (4)
Smoothed sunspot number (4) Average ap
(3)
Measured 1 AU
2014.02 170.3
(cycle peak)
166.3 146.1 (cycle peak) 110.5 (+1.2) 10.70
2014.04 143.9 144.8 112.5 116.4 (+2.1) (solar max) 7.88
2014.09 146.6 148.1 130.0 101.9 (-6.4) 9.78
2014.10 153.4 152.9 90.0 97.3 (-4.6) 8.96
2014.11 154.8 151.4 103.6 94.7 (-2.6) 9.33
2014.12 158.7 153.8 112.9 92.2 (-2.5) 11.24
2015.01 141.9 137.3 93.0 89.3 (-2.9) 9.46
2015.02 129.1 126.0 66.7 86.1 (-3.2) 9.92
2015.03 125.9 124.6 54.5 82.2 (-3.9) 16.14
2015.04 128.8 129.7 75.3 78.9 (-3.3) 10.73
2015.05 120.0 122.6 88.8 (76.3 projected, -2.6) 8.29
2015.06 122.3 126.1 66.5 (72.6 projected, -3.7) 13.15
2015.07 107.0 110.8 66.4 (68.9 projected, -3.7) 8.83
2015.08 105.4 108.0 64.6 (67.7 projected, -1.2) 14.58
2015.09 101.7 102.7 78.1 (68.0 projected, +0.3) 15.78
2015.10 104.1 103.3 61.7 (67.1 projected, -0.9) 14.02
2015.11 (110.3)   58.6 (2A) / 62.8 (2B) / 85.3 (2C) (65.0 projected, -2.1) (12.0)

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).
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 GFZ Potsdam WDC ap indices.
4) Updated to new data set from WDC-SILSO on July 1, 2015

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 Universal Time. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.