Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 9, 2015 at 05:15 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 active on January 8. Solar wind speed at SOHO ranged between 367 and 514 km/s under the influence of a high speed strem from CH649.

Solar flux at 20h UTC on 2.8 GHz was 157.2 (increasing 3.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 154.1. The Potsdam WDC planetary A index was 13 (STAR Ap - based on the mean of three hour interval ap indices: 13.3). Three hour interval K indices: 44322213 (planetary), 35233222 (Boulder).

The background x-ray flux is at the class B8 level.

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 221) and 8 active regions using 1K resolution (SN: 145) SDO images on the visible solar disk.

Region 12253 [S07W60] decayed quickly losing mature penumbra on both polarities.
Region 12255 [S15W14] decayed slowly and quietly.
Region 12257 [N05W13] developed and has two weak magnetic deltas in the trailing penumbra. An M class flare is possible.
Region 12258 [N14E52] was quiet and stable.
New region 12259 [S15E68] rotated partly into view on January 6 and was numbered by SWPC 2 days later. C and minor M class flaring is possible.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4133 [N16E02] decayed slowly and quietly.
S4134 [S09E18] was quiet and stable.
New region S4135 [N09E26] emerged fairly quickly and could produce C flares.
New region S4136 [S10E84] rotated partly into view.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C4.2/1F 04:34 S09W44 12253  
C2.6 15:48   12258  

Coronal mass ejections (CMEs)

January 6-8: 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 recurrent trans equatorial coronal hole (CH649) was in an Earth facing position on January 6-8.

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 to unsettled on January 9-11 due to effects from CH649.

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
12252 2014.12.27       S19W80         plage
12253 2014.12.29
2014.12.30
15 21 9 S06W57 0090 ESI ERI  
12255 2015.01.01 5 22 8 S14W16 0060 HSX CSO  
S4124 2015.01.02       N04W29           plage
12257 2015.01.03
2015.01.06
19 36 22 N05W16 0170 DAI DKC area: 0600

location: N05W13

S4128 2015.01.04       S19W50           plage
12258 2015.01.06 6 12 5 N13E51 0030 CRO ERO  
12259 2015.01.06
2015.01.08
6 9 4 S18E62 0200 EAO EKO area: 0320
S4133 2015.01.07   1   N16E02 0001   AXX  
S4134 2015.01.07   11 4 S09E18 0025   AXX  
S4135 2015.01.08   18 12 N09E26 0070   DRI    
S4136 2015.01.08   1 1 S10E84 0040   HAX  

 

Total spot count: 51 131 65  
Sunspot number: 101 221 145  (total spot count + 10 * number of spotted regions)
Weighted SN: 74 170 104  (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): 61 77 80 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
2015.01 146.1 (1)   27.7 (2A) / 107.4 (2B) / 88.6 (2C) (66.5 projected, -1.2) (14.8)

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.