Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 13, 2016 at 05:40 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 (February 1, 2016)
Solar cycle Solar cycles 23-24 (February 1, 2016) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24 progress (February 1, 2016) 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 (February 1, 2016) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12, 13, 14, 16 and 24 (February 1, 2016) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (January 29, 2016)  

Recent activity

The geomagnetic field was quiet to unsettled on February 12. Solar wind speed at SOHO ranged between 301 and 382 km/s. The total field of the IMF was at a high level, however, Bz was predominantly northwards resulting in only a mildly disturbed geomagnetic field. Bz at ACE swung moderately southwards after 04:30 UT on February 13, this could cause active and minor storm intervals.

Solar flux at 20h UTC on 2.8 GHz was 112.2 (increasing 12.3 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 105.4. The Potsdam WDC planetary A index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 10.8). Three hour interval K indices: 32233222 (planetary), 33233322 (Boulder).

The background x-ray flux is at the class B3 level.

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 184) and 6 active regions using 1K resolution (SN: 102) SDO images on the visible solar disk.

Region 12496 [N08W36] was quiet and stable.
Region 12497 [N13W21] has multiple magnetic deltas in the largest penumbra. Further M class flares are possible.
Region 12498 [N18E17] was quiet and stable.
New region 12499 [N11E41] rotated into view on February 10 and was numbered by SWPC 2 days later as the region began to decay.

Spotted regions not numbered (or interpreted differently) by SWPC:
S5086 [S19W20] was quiet and stable.
S5091 [N14W80] decayed slowly and quietly.
S5100 [N05E65] was quiet and stable.
New region S5102 [N25E37] emerged with a tiny spot.
New region S5103 [S34W13] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location AR Recorded by Comment
C2.1 06:36 N12W65 12492 GOES15  
M1.0 10:47   12497 GOES15  
C6.8 17:21 N12W17 12497 GOES15  
C3.0 22:39   12497 GOES15  

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

Coronal mass ejections (CMEs)

February 10, 12: No obviously Earth directed CMEs were observed in available LASCO imagery.
February 11: A halo CME was observed after the C8 LDE in AR 12497. The CME could reach Earth on February 14.

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]

An extension (CH715) of the southern polar coronal hole will rotate across the central meridian on February 13-14.

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.

Forecast

The geomagnetic field is expected to be quiet to active on February 13 with a chance of minor storm intervals. Quiet to major storm conditions are possible on February 14-15 due to effects from the February 11 CME. A high speed stream associated with CH715 could cause unsettled to minor storm conditions on February 16-17.

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
12492 2016.02.01
2016.02.02
1     N14W78 0010 AXX    

SWPC has moved AR 12492 to the location of AR S5091

spotless

12494 2016.02.03
2016.02.04
1     S14W96 0010 AXX    

rotated out of view

S5080 2016.02.03       N07W59            
12496 2016.02.04
2016.02.05
  10 5 N08W37 0020   BXO  
S5082 2016.02.04       N14W40          
12497 2016.02.05
2016.02.06
20 68 29 N13W19 0250 EAC EAC beta-gamma-delta
S5086 2016.02.05   1 1 S19W20 0004   AXX  
S5090 2016.02.06       S25W48            
S5091 2016.02.06   1   N14W80 0003   AXX  
S5092 2016.02.07       N18W44            
12498 2016.02.08
2016.02.09
1 4 3 N18E15 0010 AXX CRO  
S5094 2016.02.08       N18W16            
S5096 2016.02.09       N20W56            
12499 2016.02.10
2016.02.12
1 3 2 N11E38 0010 AXX BXO location: N11E41
S5098 2016.02.10       N22E28            
S5100 2016.02.11   4 2 N05E65 0010   BXO  
S5101 2016.02.11       S24E04          
S5102 2016.02.12   2   N25E37 0003   AXX    
S5103 2016.02.12   1   S34W13 0002   AXX    
Total spot count: 24 94 42  
Sunspot number: 74 184 102  (total spot count + 10 * number of spotted regions)
Weighted SN: 29 102 50  (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): 81 101 87 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
2014.12 158.7 153.8 112.9 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 78.8 (-3.4) 10.73
2015.05 120.0 122.6 88.8 76.0 (-2.8) 8.29
2015.06 122.3 126.1 66.5 72.0 (-4.0) 13.15
2015.07 107.0 110.8 66.4 68.2 (-3.8) 8.83
2015.08 105.4 108.0 64.6 (66.1 projected, -2.1) 14.58
2015.09 101.7 102.7 78.1 (66.1 projected, +0.0) 15.78
2015.10 104.1 103.3 61.7 (65.7 projected, -0.4) 14.02
2015.11 109.3 106.9 63.2 (63.6 projected, -2.1) 12.09
2015.12 113.1 109.5 57.7 (61.9 projected, -1.7) 14.29
2016.01 103.4 100.2 56.6 (60.2 projected, -1.7) 10.0
2016.02 113.4   31.8 (2A) / 76.8 (2B) / 89.6 (2C) (57.8 projected, -2.4) (7.9)

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).
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.