Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 20, 2014 at 04:30 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 very quiet on January 19. Solar wind speed at SOHO ranged between 270 and 306 km/s.

Solar flux at 20h UTC on 2.8 GHz was 127.5 (decreasing 8.6 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 148.2. The Potsdam WDC planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 2.1). Three hour interval K indices: 10000000 (planetary), 00102220 (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 16 active regions in 2K resolution (SN: 244) and 13 active regions in 1K resolution (SN: 179) SDO images on the visible solar disk.

Region 11949 [S15W72] decayed slowly and quietly.
Region 11952 [S32W28] gained a few spots and was quiet.
Region 11955 [S13E23] was quiet and stable.
Region 11957 [N11E21] decayed slowly and quietly.
Region 11958 [S08E50] was quiet and stable.
Region 11959 [S24E58] developed slowly and could produce C and minor M class flares.
Region 11960 [S16E63] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3029 [S26E41] was quiet and stable.
S3031 [S37E18] developed slowly and quietly.
S3038 [S02E61] was quiet and stable.
S3039 [S18E28] was quiet and stable.
New region S3043 [S15W02] emerged with a leading polarity penumbra spot early in the day, then lost that spot and gained a trailing polarity penumbra spot.
New region S3044 [S06E80] rotated into view with a penumbra spot.
New region S3045 [S12W20] emerged quickly during the latter half of the day. C flares are possible.
New region S3046 [S38W09] emerged with a penumbra spot.
New region S3047 [N19W28] emerged near the southern tip of CH600.

Coronal mass ejections (CMEs)

January 17-19: 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 northern hemisphere coronal hole (CH600) is probably too far to the north to cause geomagnetic effects, it rotated across the central meridian on January 18.

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 fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on January 20. On January 21 and 22 there is a minor chance of weak coronal hole effects from CH600, a few unsettled intervals are possible.

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
11949 2014.01.07
2014.01.08
2 3 2 S16W73 0090 HAX HAX  
11954 2014.01.08
2014.01.14
      N08W65         plage
11952 2014.01.10
2014.01.11
2 6 5 S32W29 0050 HSX CSO

area: 0080

S3011 2014.01.11       S12W55         plage
S3012 2014.01.12       N08W59           plage
S3017 2014.01.13       S30W33           plage
11956 2014.01.14
2014.01.17
      S15E08           plage
S3022 2014.01.14       S13W39           plage
S3024 2014.01.14       N15W34           plage
11955 2014.01.15
2014.01.16
2 7 3 S14E23 0060 HAX CAO area: 0100
S3027 2014.01.15       S27W41           plage
S3028 2014.01.15       N22W38           plage
S3029 2014.01.16   4   S26E41 0007   AXX  
11957 2014.01.17 9 14 10 N12E21 0030 CRI DRI area: 0060
11958 2014.01.17 1 2 1 S08E50 0040 HAX HAX area: 0080
S3031 2014.01.17   4 3 S37E18 0050   DRO  
S3032 2014.01.17       S14E11           plage
11959 2014.01.17
2014.01.18
4 15 9 S24E58 0150 DAI EKI beta-gamma

area: 0350

11960 2014.01.17
2014.01.18
1 2 1 S14E62 0150 HAX HHX area: 0380
S3035 2014.01.17       S32E04           plage
S3036 2014.01.18       N11E23         plage
S3038 2014.01.18   1   S02E61 0005   AXX  
S3039 2014.01.18   7 4 S18E28 0020   CRO  
S3040 2014.01.18       S18E52         plage
S3041 2014.01.18       S06W17         plage
S3043 2014.01.19   1 1 S15W02 0004   AXX    
S3044 2014.01.19   1   S06E80 0004   AXX    
S3045 2014.01.19   14 8 S12W20 0060   DRI    
S3046 2014.01.19   1 1 S38W09 0003   AXX    
S3047 2014.01.19   2 1 N19W28 0009   BXO    
Total spot count: 21 84 49  
Sunspot number: 91 244 179  (total spot count + 10 * number of spotted regions)
Weighted SN: 54 136 101  (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): 55 85 98 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
2014.01 164.5 (1) 82.9 (2A) / 135.3 (2B) / 100.3 (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.