Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 24, 2014 at 05:05 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 on January 23. Solar wind speed at SOHO ranged between 375 and 487 km/s under the decreasing influence of a high speed stream from CH600.

Solar flux at 20h UTC on 2.8 GHz was 136.3 (increasing 5.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 147.5. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.0). Three hour interval K indices: 22210112 (planetary), 22312221 (Boulder).

The background x-ray flux is at the class B3 level.

At the time of counting spots (see image time) spots were observed in 16 active regions in 2K resolution (SN: 298) and 12 active regions in 1K resolution (SN: 186) SDO images on the visible solar disk.

Region 11952 [S32W78] was quiet and stable.
Region 11955 [S14W31] decayed slowly and quietly.
Region 11957 [N11W37] simplified magnetically and appears to be slowly decaying.
Region 11958 [S07W03] decayed slowly and quietly.
Region 11959 [S23E05] decayed slowly and quietly.
Region 11960 [S15E10] was quiet and stable.
Region 11961 [S12W75] decayed slowly and quietly.
Region 11962 [S37W27] reemerged with penumbra spots.
Region 11963 [S06E33] was quiet and stable.
Region 11964 [S15E27] decayed slowly and quietly.
Region 11965 [S14E48] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3029 [S23W14] was quiet and stable.
S3038 [N02E07] was quiet and stable.
S3050 [S12W49] reemerged with penumbra spots.
S3053 [S08W32] reemerged with penumbra spots.
S3057 [N05E62] was quiet and stable.

Coronal mass ejections (CMEs)

January 21-23: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
January 20: An asymmetric halo CME was observed late in the day after a long duration C3 event involving AR 11963 and 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 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 24-27. On January 24 there's a chance of a few unsettled intervals if the CME observed on January 20 arrives. 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 1 1 S33W79 0030 HSX HSX

location: S32W78

11956 2014.01.14
2014.01.17
      S15W48           plage
11955 2014.01.15
2014.01.16
2 7 4 S14W31 0020 CAO CAO area: 0060
S3029 2014.01.16   12 7 S23W14 0030   BXO images\AR_S3029_20140123_2345.png  
11957 2014.01.17 12 34 20 N11W33 0080 DAI DAI

area: 0210

11958 2014.01.17 2 9 3 S08W05 0010 HRX HRX area: 0030
11962 2014.01.17
2014.01.20
  2   S37W37 0004   BXO   location: S37W27
S3032 2014.01.17       S14W41           plage
11959 2014.01.17
2014.01.18
5 25 14 S24E09 0160 CAO EHI

area: 0300

11960 2014.01.17
2014.01.18
1 8 6 S16E10 0200 HAX CHO area: 0490
S3035 2014.01.17       S32W48           plage
S3036 2014.01.18       N10W42           plage
S3038 2014.01.18   2 1 N02E07 0008   BXO  
S3039 2014.01.18       S22W21         merged with S3029
S3040 2014.01.18       S18W00           plage
S3043 2014.01.19       S15W54           plage
11963 2014.01.19
2014.01.21
3 18 4 S06E34 0010 AXX CRO area: 0030
11961 2014.01.19
2014.01.20
3 2 2 S11W76 0030 CSO CRO  
S3048 2014.01.20       N07E04           plage
S3049 2014.01.20       S10W17           plage
S3050 2014.01.20   2   S09W49 0004   AXX    
11964 2014.01.20
2014.01.21
  7   S13E26 0016   BXO  
11965 2014.01.20
2014.01.22
2 5 3 S15E46 0020 HRX CRO area: 0035
S3053 2014.01.20   2   S08W32 0004   BXO    
S3054 2014.01.21       S20E23           plage
S3055 2014.01.21       N15E45         plage
S3057 2014.01.22   2 1 N05E62 0008   BXO  
Total spot count: 31 138 66  
Sunspot number: 121 298 186  (total spot count + 10 * number of spotted regions)
Weighted SN: 67 185 113  (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): 73 104 102 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
2014.01 160.4 (1) 99.9 (2A) / 134.6 (2B) / 104.5 (2C) (67.6 projected, +0.2) (5.9)

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 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.