Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 7, 2016 at 05:55 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 6. Solar wind speed at SOHO ranged between 381 and 451 km/s.

Solar flux at 20h UTC on 2.8 GHz was 117.1 (increasing 8.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 104.8. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.5). Three hour interval K indices: 12111223 (planetary), 21221212 (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 13 active regions using 2K resolution (SN: 250) and 8 active regions using 1K resolution (SN: 129) SDO images on the visible solar disk.

Region 12491 [N02W12] decayed slowly and quietly.
Region 12492 [N13E13] was quiet and stable.
Region 12494 [S11W14] gained area and produced a few low level C flares. The region has polarity intermixing. Positive polarity flux emerged just south of the large trailing penumbra and could increase activity if more flux emerges.
Region 12495 [S08W61] decayed early in the day, after noon new flux emerged and new spots formed.
Region 12496 [N08E48] decayed early in the day, then developed and gained several small spots.
New region 12497 [N13E63] rotated into view on February 5 and was numbered the next day by SWPC. The region developed slowly during the day.

Spotted regions not numbered (or interpreted differently) by SWPC:
S5077 [S10W30] was quiet and stable.
S5080 [N05E17] was quiet and stable.
S5082 [N14E44] decayed slowly and quietly.
S5085 [N14W11] decayed slowly and quietly.
S5088 [N23W13] was quiet and stable.
New region S5090 [S19E18] was observed with a tiny spot.
New region S5091 [N14E07] emerged to the west of AR 12492 with several 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 4, 6: 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. There is a slight chance that an Earth directed component was associated 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.

Forecast

The geomagnetic field is expected to be initially quiet on February 7. Late in the day and on February 8 effects from CH713 could cause unsettled to active conditions. There's a slight chance of CME effects on February 9

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
S5061 2016.01.29       N12W41            
S5064 2016.01.29       N06W55            
12491 2016.01.30
2016.01.31
  5   N01W10 0010   BXO  
S5069 2016.01.31       S19W52            
12492 2016.02.01
2016.02.02
8 20 11 N13E10 0040 DRI DRI location: N13E13
S5071 2016.02.02       S09W30            
12493 2016.02.02
2016.02.03
      S06W73          
12494 2016.02.03
2016.02.04
9 19 10 S11W17 0230 DAI DKI

beta-gamma

area: 0350

S5076 2016.02.03       N16W19            
S5077 2016.02.03   3   S10W30 0007   AXX  
12495 2016.02.03
2016.02.05
4 15 5 S08W61 0030 CRO CRI area: 0050
S5080 2016.02.03   7 2 N05E17 0025   BXO  
12496 2016.02.04
2016.02.05
  15 4 N09E43 0010   CRI location: N08E48
S5082 2016.02.04   5   N14E44 0013   BXO  
S5083 2016.02.04       S23W49            
12497 2016.02.05
2016.02.06
10 16 10 N13E58 0050 DAI DAI area: 0090

location: N13E63

S5085 2016.02.05   1   N14W11 0002   AXX  
S5086 2016.02.05       S08E49          
S5087 2016.02.05       S05W20          
S5088 2016.02.05   1 1 N23W13 0004   HRX  
S5090 2016.02.06   1   S19E18 0003   AXX    
S5091 2016.02.06   12 6 N14E07 0040   CRI   beta-gamma
Total spot count: 31 120 49  
Sunspot number: 71 250 129  (total spot count + 10 * number of spotted regions)
Weighted SN: 47 150 79  (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): 78 138 110 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
2016.02 112.4   15.6 (2A) / 75.2 (2B) / 81.4 (2C) (57.8 projected, -2.4) (7.4)

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.