Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 19, 2016 at 04:35 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 unsettled to minor storm on February 18 under the influence of a high speed stream from CH715. Solar wind speed at SOHO ranged between 548 and 663 km/s.

Solar flux at 20h UTC on 2.8 GHz was 94.9 (decreasing 5.6 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 105.2. The Potsdam WDC planetary A index was 26 (STAR Ap - based on the mean of three hour interval ap indices: 25.9). Three hour interval K indices: 45443443 (planetary), 35453343 (Boulder).

The background x-ray flux is at the class B4 level.

At the time of counting spots (see image time), spots were observed in 11 active regions using 2K resolution (SN: 168) and 9 active regions using 1K resolution (SN: 110) SDO images on the visible solar disk.

Region 12501 [N04E24] was quiet and stable.
Region 12502 [N08W29] decayed slowly and quietly.
Region 12503 [N05W13] decayed slowly and quietly.

Spotted regions not numbered (or interpreted differently) by SWPC:
S5109 [S03E03] was quiet and stable.
S5111 [S19E15] reemerged with tiny spots.
S5113 [N07W03] developed slowly and quietly.
New region S5115 [N12E11] emerged with a tiny spot.
New region S5116 [N09E03] emerged with a few spots.
New region S5117 [N32W08] was observed with tiny spots.
New region S5118 [S55E45] emerged with a tiny spot at a high latitude.
New region S5119 [S41W31] was observed with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location AR Recorded by Comment
C7.2 01:58   12497 GOES15  

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

Coronal mass ejections (CMEs)

February 16-18: 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. The southern parts of a large, recurrent northern hemisphere coronal hole (CH716) could rotate into an Earth facing position on February 20-22. CH716 was too far to the north to cause a disturbance during the previous rotation.

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 fair to good.

Forecast

The geomagnetic field is expected to be quiet to active on February 19 due to effects from CH715, quiet to unsettled on February 20 and quiet on February 21-22.

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
12498 2016.02.08
2016.02.09
      N18W68            
12499 2016.02.10
2016.02.12
      N11W43            
12503 2016.02.11
2016.02.17
1 9 3 N06W14 0010 AXX CRO  
S5102 2016.02.12       N24W34          
S5105 2016.02.13       S11W20            
12502 2016.02.13
2016.02.16
3 11 4 N08W29 0010 BXO CRO area: 0025
12501 2016.02.14 1 8 2 N05E20 0050 HSX CSI area: 0110

location: N04E24

S5108 2016.02.15       N26E08            
S5109 2016.02.15   7 2 S03E03 0015   AXX  
S5110 2016.02.15       S38W21            
S5111 2016.02.16   3 1 S19E15 0008   BXO    
S5112 2016.02.16       S09W05          
S5113 2016.02.17   9 5 N07W03 0030   CRO  
S5114 2016.02.17       N12W36          
S5115 2016.02.18   1 1 N12E11 0004   AXX    
S5116 2016.02.18   6 2 N09E03 0014   DRO    
S5117 2016.02.18   2   N32W08 0003   AXX    
S5119 2016.02.18   1   S55E45 0001   AXX    
S5120 2016.02.18   1   S41W31 0002   AXX    
Total spot count: 5 58 20  
Sunspot number: 35 168 110  (total spot count + 10 * number of spotted regions)
Weighted SN: 10 75 38  (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): 39 92 94 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 (110.3)   41.8 (2A) / 67.3 (2B) / 89.1 (2C) (57.8 projected, -2.4) (11.5)

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.