Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 4, 2016 at 04:40 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 active on February 3. Solar wind speed at SOHO ranged between 342 and 411 km/s under the influence of effects from CH712.

Solar flux at 20h UTC on 2.8 GHz was 112.1 (increasing 8.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 104.7. The Potsdam WDC planetary A index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 10.9). Three hour interval K indices: 44311111 (planetary), 54322212 (Boulder).

The background x-ray flux is at the class B6 level.

At the time of counting spots (see image time), spots were observed in 13 active regions using 2K resolution (SN: 283) and 9 active regions using 1K resolution (SN: 149) SDO images on the visible solar disk.

Region 12489 [N10W72] was quiet and stable.
Region 12490 [S19W56] developed further and could produce C flares.
Region 12491 [N02E30] developed slowly and quietly.
Region 12492 [N14E51] gained a few spots and was mostly quiet.
New region 12493 [S07W30] emerged on February 2 with SWPC numbering the region the next day as it developed further. The region has a weak magnetic delta and could produce a minor M class flare if the region develops further.

Spotted regions not numbered (or interpreted differently) by SWPC:
S5061 [N12W02] was quiet and stable.
S5064 [N06W16] was quiet and stable.
New region S5074 [S12E23] emerged quickly early in the day with many spots and polarity intermixing. C flares are possible.
New region S5076 [N15E20] emerged with tiny spots.
New region S5077 [S14E10] was observed with tiny spots.
New region S5078 [S08W18] emerged with several spots.
New region S5079 [S26W46] was observed with a tiny spot.
New region S5080 [N06E58] was observed with tiny spots in an old plage area.

With the new images it's possible to observe tiny spots near the poles. This is a bipolar region observed at S63E25 with two extremely small spots only visible at 4K resolution

 

C2+ flares:

Magnitude Peak time (UT) Location AR Recorded by Comment
           

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

Coronal mass ejections (CMEs)

January 31 - February 2: 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]

A trans equatorial coronal hole (CH712) rotated across the central meridian on January 30-31. A recurrent trans equatorial coronal hole (CH713) will likely rotate into a potentially geoeffective position on February 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.

Forecast

The geomagnetic field is expected to be quiet on February 4-6.

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
10 26 12 S21W56 0060 DAO DAI

area: 0130

location: S19W56

12489 2016.01.24
2016.01.25
2 6 2 N09W72 0200 HAX CAO

area: 0220

S5056 2016.01.26       N25W54            
S5061 2016.01.29   6 1 N12W02 0012   BXO images/AR_S5061_20160203_2345.png  
S5062 2016.01.29       N10W57            
S5064 2016.01.29   6   N06W16 0010   BXO  
12491 2016.01.30
2016.01.31
6 29 13 N03E30 0030 DRO DAI area: 0080
S5066 2016.01.30       N09W35            
S5068 2016.01.30       S21W34            
S5069 2016.01.31       S19W13            
12492 2016.02.01
2016.02.02
5 16 6 N15E49 0060 DSI DAI  
S5071 2016.02.02       S09E09         images/AR_S5071_20160202_2345.png  
12493 2016.02.02
2016.02.03
5 19 9 S06W31 0030 DAO DAC area: 0090
S5073 2016.02.02       S10W36          
S5074 2016.02.03   22 11 S12E23 0080   DRI    
S5076 2016.02.03   2 1 N15E20 0005   BXO    
S5077 2016.02.03   8   S14E10 0020   BXO    
S5078 2016.02.03   10 4 S08W18 0030   CRI    
S5079 2016.02.03   1   S26W46 0001   AXX    
S5080 2016.02.03   2   N06E58 0002   BXO    
Total spot count: 28 153 59  
Sunspot number: 78 283 149  (total spot count + 10 * number of spotted regions)
Weighted SN: 51 184 90  (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): 86 156 127 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
2016.02 104.8   5.9 (2A) / 57.3 (2B) / 75.0 (2C) (57.8 projected, -2.4) (7.7)

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.