Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 6, 2016 at 07:00 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 5. Solar wind speed at SOHO ranged between 342 and 463 km/s.

Solar flux at 20h UTC on 2.8 GHz was 119.7 (increasing 12.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 104.8. The Potsdam WDC planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 10.1). Three hour interval K indices: 33222232 (planetary), 34332322 (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 15 active regions using 2K resolution (SN: 273) and 13 active regions using 1K resolution (SN: 175) SDO images on the visible solar disk.

Region 12490 [S20W83] decayed slowly and quietly.
Region 12491 [N02E06] decayed slowly and quietly.
Region 12492 [N13E25] lost some penumbral area while gaining a few small spots.
Region 12493 [S05W57] decayed slowly and quietly.
Region 12494 [S11W02] matured and lost the magnetic delta. C flares are possible and there is a minor chance of a small M class event.
New region 12495 [S08W48] emerged on February 3 and was numbered by SPWC 2 days later when the region began to decay.
New region 12496 [N08E59] rotated into view on February 4 and got its NOAA number the next day as the region decayed.

Spotted regions not numbered (or interpreted differently) by SWPC:
S5077 [S10W19] was quiet and stable.
S5080 [N05E30] developed slightly and was quiet.
S5082 [N13E57] gained spots and was quiet.
New region S5084 [N13E74] rotated into view.
New region S5085 [N13E02] was observed with tiny spots.
New region S5086 [S08E62] was observed with a tiny spot.
New region S5087 [S05W07] emerged with a tiny spot.
New region S5088 [N24E01] emerged with a few spots.

C2+ flares:

Magnitude Peak time (UT) Location AR Recorded by Comment
C3.0 00:56   12494 GOES15  
C2.9 07:22 S12E06 12494 GOES15  

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

Coronal mass ejections (CMEs)

February 3-4: No obviously Earth directed CMEs were observed in available LASCO imagery.
February 5: A filament eruption to the west of AR 12494 was observed beginning near 20h UT. A slow moving partial halo CME was observed late on February 5 and early on February 6 in LASCO imagery. It is not yet certain if the CME was associated with the filament eruption, however, it appears to be the most likely cause. In that case there is a slight chance there was an Earth directed component with this CME.

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 trans equatorial coronal hole (CH713) rotated across the central meridian on February 4-5.

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 unsettled on February 6. Late on February 7 and on February 8 effects from CH713 could cause unsettled to active conditions.

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
12490 2016.01.24
2016.01.25
5 6 3 S20W81 0080 CAO CAO  
S5061 2016.01.29       N12W28         images/AR_S5061_20160203_2345.png  
S5062 2016.01.29       N10W83            
S5064 2016.01.29       N06W42            
12491 2016.01.30
2016.01.31
2 12 2 N02E03 0010 AXX BXO area: 0020
S5068 2016.01.30       S21W58            
S5069 2016.01.31       S19W39            
12492 2016.02.01
2016.02.02
8 32 11 N14E23 0050 DSO DRI  
S5071 2016.02.02       S09W17            
12493 2016.02.02
2016.02.03
5 8 3 S05W58 0010 DRO DRO  
12494 2016.02.03
2016.02.04
16 23 10 S12W04 0230 DAI DAI

area: 0320

S5076 2016.02.03       N16W06          
S5077 2016.02.03   3   S10W19 0007   AXX  
12495 2016.02.03
2016.02.05
6 7 4 S07W46 0010 BXO DRO area: 0020
S5080 2016.02.03   8 2 N05E30 0015   BXO  
12496 2016.02.04
2016.02.05
  5 1 N09E56 0010 AXX BXO location: N08E59
S5082 2016.02.04   9 4 N13E57 0020   BXO  
S5083 2016.02.04       S23W36          
S5084 2016.02.05   3 1 N13E74 0030   CAO    
S5085 2016.02.05   2 1 N13E02 0005   AXX    
S5086 2016.02.05   1   S08E62 0001   AXX    
S5087 2016.02.05   1 1 S05W07 0003   AXX    
S5088 2016.02.05   3 2 N24E01 0010   CRO    
Total spot count: 42 123 45  
Sunspot number: 112 273 175  (total spot count + 10 * number of spotted regions)
Weighted SN: 60 150 72  (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): 123 150 149 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
2016.02 111.5   13.1 (2A) / 76.0 (2B) / 80.3 (2C) (57.8 projected, -2.4) (7.6)

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.