Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 16, 2015 at 02:55 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 December 27, 2014]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to unsettled on January 15. Solar wind speed at SOHO ranged between 351 and 435 km/s.

Solar flux at 20h UTC on 2.8 GHz was 131.4 (decreasing 84.3 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 155.6. 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: 00113100 (planetary), 01222321 (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: 157) and 7 active regions using 1K resolution (SN: 107) SDO images on the visible solar disk.

Region 12258 [N14W47] decayed slowly and quietly.
Region 12259 [S16W21] decayed losing penumbral area. The region still has polarity intermixing and could produce C flares.
Region 12260 [N08W75] decayed slowly and quietly.
Region 12261 [S11W07] decayed slowly and quietly.
New region 12263 [N22E50] emerged on January 14 and was numbered by SWPC the next day.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4134 [S25W49] decayed slowly and quietly.
S4148 [S14E48] was quiet and stable.
S4149 [S07E59] was quiet and stable.
S4150 [N09E61] was quiet and stable.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C2.1 02:39 S03W72 12262  
C2.4 (LDE) 03:34   12257  
C2.4 14:59   12255  
C2.6 16:49     filament eruption northern hemisphere

Coronal mass ejections (CMEs)

January 13-15: No obviously Earth directed CMEs were observed in 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 (CH650) was in an Earth facing position on January 14-15.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle latitudes is fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be mostly quiet on January 16. A high speed stream from CH650 could cause unsettled and active intervals on January 17-18.

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
12258 2015.01.06   1   N16W44 0003   AXX  
12259 2015.01.06
2015.01.08
13 37 18 S16W24 0160 DAC DAC beta-gamma

location: S16W21

S4134 2015.01.07   1   S25W49 0003   AXX  
12260 2015.01.08
2015.01.09
4 7 5 N09W74 0060 CSO BXO  
12261 2015.01.08
2015.01.09
1 5 2 S11W09 0020 HAX CRO  
12262 2015.01.10       S01W83        

plage

S4141 2015.01.10       S01W30           plage
S4143 2015.01.11       S09W58         plage
S4145 2015.01.12       N09W05           plage
S4146 2015.01.12       N36W04         plage
S4147 2015.01.12       S30W09           plage
S4148 2015.01.14   5 3 S14E38 0015   AXX  
S4149 2015.01.14   2 2 S07E59 0007   AXX  
S4150 2015.01.14   1 1 N09E61 0005   HRX  
12263 2015.01.14
2015.01.15
4 8 6 N22E50 0030 CRO DRO

 

Total spot count: 22 67 37  
Sunspot number: 62 157 107  (total spot count + 10 * number of spotted regions)
Weighted SN: 40 81 51  (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): 37 55 59 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
2015.01 147.0 (1)   52.2 (2A) / 107.9 (2B) / 84.9 (2C) (66.5 projected, -1.2) (10.9)

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.