Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 26, 2015 at 03:50 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update January 1, 2015)] [Cycle 24 progress (last update January 1, 2015) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update January 1, 2015)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update January 1, 2015)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update January 3, 2015)]

[Noon SDO sunspot count 1K Reference: 4K (large file) (updated daily)]

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated January 25, 2015]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to unsettled on January 25. Solar wind speed at SOHO ranged between 310 and 379 km/s.

Solar flux at 20h UTC on 2.8 GHz was 126.6 (decreasing 4.9 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 146.9. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.8). Three hour interval K indices: 12001113 (planetary), 11012223 (Boulder).

The background x-ray flux is at the class B5 level.

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 188) and 8 active regions using 1K resolution (SN: 140) SDO images on the visible solar disk.

Region 12266 [S05W85] was quiet and stable.
Region 12268 [S10E34] developed in the trailing spot section with a small magnetic delta forming. A minor M class flare is possible.
Region 12269 [N07W07] was quiet and stable.
New region 12271 [N17E10] emerged on January 23 and was numbered by SWPC 2 days later. The region has polarity intermixing and could produce C flares.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4166 [S27W10] reemerged with a penumbra spot.
New region S4174 [S10E74] rotated into view with penumbra spots.
New region S4175 [N12E75] rotated into view.
New region S4176 [S03E07] emerged with several spots. The region has reversed polarities.
New region S4177 [S03W04] emerged with a few spots.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
         

Coronal mass ejections (CMEs)

January 23-25: No obviously Earth directed CMEs were observed in LASCO imagery. There may have been a weak CME after 15h UTC on January 24 following a filament eruption.

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 small southern hemisphere coronal hole (CH651) was in an Earth facing position on January 25.

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 to fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on January 26. On January 27 there is a slight chance of CME effects due to a filament eruption on January 24. On January 28-29 a weak coronal hole stream could cause some unsettled intervals.

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) 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 overlay
Comment
SWPC Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12266 2015.01.14
2015.01.18
3 2 1 S05W84 0050 CAO CSO

 

12264 2015.01.14
2015.01.16
      N09W79           plage
12263 2015.01.14
2015.01.15
      N21W89           plage
12267 2015.01.18
2015.01.19
      N18W21           plage
S4155 2015.01.18       S15W46         plage
S4156 2015.01.18       N19W54           plage
12269 2015.01.19
2015.01.22
3 21 12 N09W06 0010 BXO DRO area: 0050

location: N07W07

12268 2015.01.21
2015.01.22
10 42 29 S10E35 0360 EKI FKO beta-gamma-delta

area: 0530

S4163 2015.01.21       N00W52         plage
12270 2015.01.22
2015.01.23
      S18E27         plage
S4166 2015.01.22   1   S27W10 0003   AXX   plage
S4167 2015.01.22       N02W19           plage
S4168 2015.01.23       S10W01         plage
12271 2015.01.23
2015.01.25
9 18 8 N18E09 0040 CAO DRI beta-gamma

area: 0090

S4172 2015.01.24       S24E11         plage
S4173 2015.01.24       S04W21         plage
S4174 2015.01.25   3 2 S10E74 0010   BXO    
S4175 2015.01.25   1 1 N12E75 0030   HRX    
S4176 2015.01.25   8 5 S03E17 0025   DRO    
S4177 2015.01.25   2 2 S03E06 0012   CRO  

 

Total spot count: 25 98 60  
Sunspot number: 65 188 140  (total spot count + 10 * number of spotted regions)
Weighted SN: 45 128 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): 39 66 77 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for MSN 2K, k = 0.55 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number Average ap
(3)
Measured 1 AU
2013.09 102.6 103.7 36.9 73.1 (+4.1) 5.23
2013.10  132.1 131.2 85.6 75.0 (+1.9) 7.71
2013.11  148.3 145.1 77.6 75.4 (+0.4) 5.68
2013.12 147.7 143.1 90.3 76.0 (+0.6) 4.68
2014.01 157.4 152.4 81.8 77.3 (+1.3) 5.44
2014.02 170.3
(cycle peak)
166.3 102.3 (cycle peak) 78.4 (+1.1) 10.70
2014.03 149.9 148.5 91.9 80.8 (+2.4) 4.88
2014.04 143.9 144.8 84.7 81.9 (+1.1)
(likely solar max)
7.88
2014.05 129.7 132.9 75.2 80.5 (-1.4) 5.75
2014.06 122.0 125.8 71.0 79.7 (-0.8) 6.72
2014.07 137.4 141.8 72.5 (78.6 projected, -1.1) 4.50
2014.08 124.7 127.9 74.7 (76.2 projected, -2.4) 7.71
2014.09 146.6 148.1 87.6 (73.0 projected, -3.2) 9.78
2014.10 153.4 152.9 60.6 (70.5 projected, -2.5) 8.96
2014.11 154.8 151.4 70.1 (68.8 projected, -1.7) 9.33
2014.12 158.7 153.8 78.0 (67.7 projected, -1.1) 11.24
2015.01 138.0 (1)   72.4 (2A) / 89.8 (2B) / 72.3 (2C) (66.5 projected, -1.2) (9.0)

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). The official WDC-SILSO international sunspot number is typically 30-50% lower. 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.

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 the UTC day. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.