Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 23, 2016 at 04:10 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 very quiet on February 22. Solar wind speed at SOHO ranged between 306 and 348 km/s.

Solar flux at 20h UTC on 2.8 GHz was 93.7 (decreasing 21.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 104.2. 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: 00011101 (planetary), 00012111 (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: 129) and 3 active regions using 1K resolution (SN: 42) SDO images on the visible solar disk.

Region 12501 [N05W30] decayed slowly and quietly.
Region 12504 [N13W41] decayed slowly and quietly.
Region 12505 [N08W56] decayed slowly and quietly.

Spotted regions not numbered (or interpreted differently) by SWPC:
S5109 [S03W52] reemerged with tiny spots.
S5111 [S27W15] was quiet and stable.
S5121 [N11E38] was quiet and stable.
S5124 [S23E57] was quiet and stable.
New region S5126 [S08E78] rotated into view with tiny spots.

C2+ flares:

Magnitude Peak time (UT) Location AR Recorded by Comment
           

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

Coronal mass ejections (CMEs)

February 20-22: 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]

The southern parts of a large, recurrent northern hemisphere coronal hole (CH716) was in 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 to fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet to unsettled on February 23 becoming quiet to active on February 24-25 due to a high speed stream.

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
12503 2016.02.11
2016.02.17
      N05W70          

 

12502 2016.02.13
2016.02.16
      N07W84            
12501 2016.02.14 1 9 3 N04W32 0060 HSX CSO  
S5108 2016.02.15       N26W44            
S5109 2016.02.15   4   S03W52 0005   AXX    
S5111 2016.02.16   2   S27W15 0004   AXX images/AR_S5111_20160221_2345.png  
S5112 2016.02.16       S09W57            
12505 2016.02.17
2016.02.20
8 17 8 N08W56 0160 DAC EAC  
12504 2016.02.18
2016.02.19
  2   N13W41 0002   BXO  
S5116 2016.02.18       N08W50            
S5119 2016.02.18       S55W07            
S5121 2016.02.19   10   N11E38 0015   BXO  
S5124 2016.02.21   3   S23E57 0007   AXX  
S5126 2016.02.22   2 1 S08E78 0005   AXX    
Total spot count: 9 49 12  
Sunspot number: 29 129 42  (total spot count + 10 * number of spotted regions)
Weighted SN: 19 59 22  (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): 32 58 34 k * (sunspot number)
As of February 19, 2015: k = 1.1 for SWPC, k = 0.45 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
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 (107.7)   47.4 (2A) / 62.5 (2B) / 82.2 (2C) (57.8 projected, -2.4) (10.8)

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.