Solar Terrestrial Activity Report

Activity chart

Last major update issued on December 1, 2016 at 06:55 UT.

Charts (* = updated daily) Data and archive
  Solar wind (*) Solar and geomagnetic data - last month (*)
  Electron fluence (*) Archived daily reports and monthly data since 2003.01 (November 6, 2016)
Solar cycle Solar cycles 23-24 (December 1, 2016) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24 progress (December 1, 2016) Noon SDO sunspot count 1K / 4K (*)
  Solar cycles 1-24 (July 17, 2015) POES auroral activity level October 2009 - December 2012
  Comparison of cycles 21, 22, 23 and 24 (December 1, 2016) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12, 13, 14, 16 and 24 (December 1, 2016) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (October 30, 2016)  

Recent activity

The geomagnetic field was very quiet on November 30. Solar wind speed at SOHO ranged between 334 and 364 km/s.

Solar flux at 20h UTC on 2.8 GHz was 83.6 (increasing 8.0 over the last solar rotation). The average 90 day 10.7 flux at 1 AU was 83.6. The Potsdam WDC planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 2.0). Three hour interval K indices: 11100000 (planetary), 11211210 (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 7 active regions using 2K resolution (SN: 119) and 7 active regions using 1K resolution (SN: 104) SDO images on the visible solar disk.

Region 12612 [N09W22] decayed slowly and quietly.
Region 12614 [N05E08] decayed slowly and quietly.
Region 12615 [S07E35] lost the magnetic delta but still has minor polarity intermixing. Occasional C class flaring is possible.

Spotted regions not numbered (or interpreted differently) by SWPC:
S5516 [N17E09] was quiet and stable.
S5520 [S24E35] was quiet and stable.
S5522 [N08W09] was quiet and stable.
New region S5523 [S01E59] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location AR Recorded by Comment
C6.0 01:19 S08E51 12615 GOES15  
C3.1 02:24 S08E51 12615 GOES15  
C2.3 15:25 S07E43 12615 GOES15  

 

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

Coronal mass ejections (CMEs)

November 28-30: 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 small southern hemisphere coronal hole (CH776) will rotate into an Earth facing position on December 1. CH776 didn't cause a geomagnetic disturbance during the previous solar rotation.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle latitudes is fair to good. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on December 1-3. On December 4-5 there is a chance of unsettled intervals due to effects from CH776.

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). 4K 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
12612 2016.11.22
2016.11.23
34 12 8 N08W23 0110 DSO CAO Either a typo or a major observational error by SWPC. If a type the spot count would probably by similar to the previous day: 4
S5513 2016.11.25       S27W25            
S5515 2016.11.27       S17W11            
S5516 2016.11.27   2 1 N17E09 0005   AXX  
12614 2016.11.28 3 16 9 N05E06 0060 DAO DAO  
12615 2016.11.28
2016.11.29
8 14 13 S07E37 0060 DAI DAI location: S07E35

area: 0100

beta-gamma

S5519 2016.11.28       S04W53            
S5520 2016.11.29   2 1 S24E35 0006   BXO  
S5521 2016.11.29       N13E06          
S5522 2016.11.29   2 1 N08W09 0005   BXO  
S5523 2016.11.30   1 1 S01E59 0004   AXX    
Total spot count: 45 49 34  
Sunspot number: 75 119 104  (total spot count + 10 * number of spotted regions)
Weighted SN: 60 64 49  (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): 83 65 83 k * (sunspot number)
As of May 7, 2016: k = 1.1 for SWPC, k = 0.55 for MSN 2K, k = 0.80 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
2015.09 101.7 102.7 78.6 65.9 (-0.5) 15.78
2015.10 104.1 103.3 63.6 64.3 (-1.6) 14.02
2015.11 109.3 106.9 62.2 61.3 (-3.0) 12.09
2015.12 113.1 109.5 58.0 57.8 (-3.5) 14.29
2016.01 103.4 100.1 57.0 54.4 (-3.4) 9.4
2016.02 103.6 101.0 56.4 52.5 (-1.9) 9.9
2016.03 91.5 90.6 54.1 50.5 (-2.0) 10.58
2016.04 93.3 94.0 38.0 47.8 (-2.7) 9.03
2016.05 93.0 95.3 52.1 44.9 (-2.9) 11.65
2016.06 81.9 84.5 20.9 (42.0 projected, -2.9) 8.44
2016.07 86.0 88.9 32.5 (39.1 projected, -2.9) 9.43
2016.08 85.0 87.1 50.7 (36.3 projected, -2.8) 9.61
2016.09 87.7 88.7 44.7 (33.6 projected, -2.7) 14.54
2016.10 86.1 85.6 33.6 (31.6 projected, -2.0) 15.33
2016.11 78.6 76.9 21.4 (29.8 projected, -1.8) 8.6
2016.12 ()   0.0 (2A/2B) / 27.5 (2C) (28.3 projected, -1.5) ()

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.