Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 25, 2014 at 06:55 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, 2014)] [Cycle 24 progress (last update January 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update January 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update January 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update January 1, 2014)]

[POES auroral activity level since October 2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated January 11, 2014]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet to unsettled on January 24. Solar wind speed at SOHO ranged between 338 and 374 km/s.

Solar flux at 20h UTC on 2.8 GHz was 135.5 (increasing 1.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 147.2. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.9). Three hour interval K indices: 32000011 (planetary), 21002221 (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 15 active regions in 2K resolution (SN: 296) and 12 active regions in 1K resolution (SN: 199) SDO images on the visible solar disk.

Region 11955 [S14W45] decayed slowly and quietly.
Region 11957 [N10W48] decayed fairly quickly and was quiet.
Region 11958 [S08W13] decayed slowly and quietly.
Region 11959 [S23W07] developed slowly with more intermediate spots emerging.
Region 11960 [S16W02] developed slowly and quietly.
Region 11962 [S37W38] was quiet and stable.
Region 11963 [S08E19] decayed slowly and quietly.
Region 11964 [S14E15] was quiet and stable.
Region 11965 [S13E40] decayed in the leading spot section while development was observed in the trailing spot section. The region is being considered for a split.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3029 [S23W14] was quiet and stable.
S3038 [N00W09] was quiet and stable.
New region S3059 [N02W07] emerged close to AR S3038 on January 23 and was split off the next day. The region developed slowly and has spots in both polarities early in the day, then decayed.
New region S3060 [S01E32] emerged with a penumbra spot.
New region S3061 [N08E26] emerged with a penumbra spot.
New region S3062 [S28E23] emerged with penumbras spots.

Coronal mass ejections (CMEs)

January 22-24: No obviously Earth directed CMEs were observed in LASCO and STEREO 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 small northern hemisphere coronal hole (CH601) will likely rotate into an Earth facing position on January 25.

Coronal hole map

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 on January 25-27. On January 28-29 effects from CH601 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: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% 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 STAR SDO SWPC STAR Current Previous
2K 1K
11952 2014.01.10
2014.01.11
1     S31W90 0030 HSX    

rotated out of view

11956 2014.01.14
2014.01.17
      S15W62           plage
11955 2014.01.15
2014.01.16
4 5 3 S12W45 0020 CAO HRX  
S3029 2014.01.16   7 4 S23W24 0025   AXX images\AR_S3029_20140123_2345.png  
11957 2014.01.17 26 30 17 N12W46 0170 EAI DAI

area: 0140

11958 2014.01.17 1 10 6 S07W18 0010 HRX BXO area: 0020
11962 2014.01.17
2014.01.20
  2   S37W51 0004   AXX location: S37W38
S3032 2014.01.17       S14W54           plage
11959 2014.01.17
2014.01.18
11 37 18 S23W05 0180 EAO DHI

area: 0350

11960 2014.01.17
2014.01.18
6 19 16 S16W03 0220 HAX CHO area: 0500
S3036 2014.01.18       N10W55           plage
S3038 2014.01.18   1 1 N00W09 0004   AXX  
S3040 2014.01.18       S18W13           plage
11963 2014.01.19
2014.01.21
8 17 7 S07E18 0010 AXX BXO area: 0030
11961 2014.01.19
2014.01.20
1     S06W91 0030 HSX     rotated out of view
S3048 2014.01.20       N07W09           plage
S3049 2014.01.20       S10W30           plage
11964 2014.01.20
2014.01.21
  5   S13E12 0009   BXO  
11965 2014.01.20
2014.01.22
2 8 4 S16E31 0010 AXX ERO area: 0045

candidate for region split

S3053 2014.01.20       S08W45         plage
S3054 2014.01.21       S20E10           plage
S3055 2014.01.21       N15E32           plage
S3057 2014.01.22       N05E49         plage
S3059 2014.01.24   1 1 N02W07 0003   AXX    
S3060 2014.01.24   1   S01E32 0002   AXX    
S3061 2014.01.24   1 1 N08E26 0006   AXX    
S3062 2014.01.24   2 1 S28E23 0005   AXX    
Total spot count: 60 146 79  
Sunspot number: 150 296 199  (total spot count + 10 * number of spotted regions)
Weighted SN: 93 177 110  (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): 90 104 109 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for STAR SDO 2K, k = 0.55 for STAR SDO 1K

Monthly solar cycle data

Month Average measured solar flux International sunspot number (SIDC) Smoothed sunspot number Average ap
(3)
2011.11 153.5 (cycle peak) 96.7 (cycle peak) 61.1 (+1.2) 5.55
2012.02 106.5 32.9 66.9 (+1.4)
possible cycle 24 max
8.81
2012.10 123.3 53.3 58.6 (+0.5) 9.97
2012.11 121.3 61.8 59.7 (+1.1) 7.08
2012.12 108.6 40.8 59.6 (-0.1) 3.44
2013.01 127.1 62.9 58.7 (-0.9) 4.69
2013.02 104.3 38.0 58.4 (-0.3) 6.11
2013.03 111.3 57.9 57.5 (-0.9) 10.56
2013.04 124.8 72.4 57.9 (+0.4) 5.40
2013.05 131.4 78.7 59.9 (+2.0) 9.73
2013.06 110.1 52.5 62.6 (+2.7) 12.60
2013.07 115.5 57.0 (65.4 projected, +2.8) 9.47
2013.08 114.6 66.0 (67.8 projected, +2.4) 8.27
2013.09 102.6 36.9 (70.1 projected, +2.3) 5.23
2013.10  132.1 85.6 (70.0 projected, -0.1) 7.71
2013.11  148.3 77.6 (68.1 projected, -1.9) 5.68
2013.12 147.7 90.3 (67.4 projected, -0.7) 4.68
2014.01 159.3 (1) 104.7 (2A) / 135.3 (2B) / 105.6 (2C) (67.6 projected, +0.2) (5.8)

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 SIDC 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 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.