Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 16, 2016 at 04:35 UT. Active region data to be updated later in the day.

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 active on February 15. Solar wind speed at SOHO ranged between 348 and 445 km/s. A disturbance began late in the day, it is not yet clear whether the source is the late arrival of the Feb.11 CME (low level protons at ACE does not indicate a CME) or a co-rotating interaction region associated with CH715.

Solar flux at 20h UTC on 2.8 GHz was 107.3 (increasing 9.6 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 105.5. The Potsdam WDC planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 9.4). Three hour interval K indices: 23321114 (planetary), 23322223 (Boulder).

The background x-ray flux is at the class B7 level.

At the time of counting spots (see image time), spots were observed in 10 active regions using 2K resolution (SN: 168) and 5 active regions using 1K resolution (SN: 77) SDO images on the visible solar disk.

Region 12497 [N12W64] lost penumbral area while maintaining magnetic deltas in the central part of the region. Very frequent C class flaring was observed. Further M class flaring is likely.
Region 12499 [N10E01] regained tiny spots.
Region 12500 [S17W55] decayed slowly and quietly.
Region 12501 [N04E64] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S5100 [N05E23] was quiet and stable.
S5102 [N21W02] regained tiny spots.
S5106 [N08E14] developed slowly and quietly.
New region S5108 [N26E47] emerged as a bipolar region early in the day and decayed slowly during the latter half of the day.
New region S5109 [S03E41] was observed with tiny spots.
New region S5110 [S38E18] emerged with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location AR Recorded by Comment
C3.9 04:19   12497 GOES15  
C5.2 08:41 N12W54 12497 GOES15  
C2.3/1F 09:35 N10W52 12497 GOES15  
C2.7 10:10   12497 SDO/EVE  
C3.6 10:49   12497 SDO/EVE  
M1.1/1N 11:00 N10W52 12497 GOES15  
C2.8 13:08   12497 SDO/EVE  
C3.1 13:35   12497 SDO/EVE  
C3.3 15:04 N14W58 12497 GOES15  
C2.5 17:23 N14W58 12497 GOES15  
C4.2 17:52   12497 GOES15  
C2.2 18:12   12497 GOES15  
C2.9 18:46 N14W58 12497 GOES15  
C4.8 21:24   12497 SDO/EVE  
C4.1 21:40   12497 GOES15  

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

Coronal mass ejections (CMEs)

February 13-15: 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]

An extension (CH715) of the southern polar coronal hole rotated 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 to fair.

Forecast

The geomagnetic field is expected to be quiet to minor storm on February 16-17 due to effects from CH715.

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
12496 2016.02.04
2016.02.05
      N08W65          
12497 2016.02.05
2016.02.06
18 42 24 N12W48 0200 EAC EAC gamma-delta

area: 0300

S5086 2016.02.05       S19W49            
12498 2016.02.08
2016.02.09
  2   N18W12 0002   BXO location: N21W03
S5094 2016.02.08       N18W42            
12499 2016.02.10
2016.02.12
      N11E11          
S5098 2016.02.10       N22W11            
S5100 2016.02.11   3   N05E43 0005   AXX  
S5101 2016.02.11       S24W22            
S5102 2016.02.12       N25E11            
S5103 2016.02.12       S34W39            
12500 2016.02.13 3 7 3 S18W42 0020 CRO DRO  
S5105 2016.02.13       S11E32          
S5106 2016.02.13   2 1 N09E25 0012   AXX  
S5107 2016.02.13       S08W28          
12501 2016.02.14 1 1 1 N04E76 0060 HSX HSX    
Total spot count: 22 57 29  
Sunspot number: 52 117 69  (total spot count + 10 * number of spotted regions)
Weighted SN: 35 70 42  (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): 57 64 59 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
2016.01 103.4 100.1 56.6 (60.2 projected, -1.7) 9.4
2016.02 112.8   35.2 (2A) / 72.9 (2B) / 90.2 (2C) (57.8 projected, -2.4) (7.8)

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.