Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 17, 2014 at 04:40 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 16. Solar wind speed at SOHO ranged between 353 and 477 km/s.

Solar flux at 20h UTC on 2.8 GHz was 121.0 (decreasing 28.2 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 148.5. The Potsdam WDC planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 1.6). Three hour interval K indices: 00110000 (planetary), 00211211 (Boulder).

The background x-ray flux is at the class C1 level.

At the time of counting spots (see image time) spots were observed in 10 active regions in 2K resolution (SN: 149) and 9 active regions in 1K resolution (SN: 114) SDO images on the visible solar disk.

Region 11948 [N06W67] decayed slowly and quietly.
Region 11949 [S16W32] was quiet and stable.
Region 11950 [N16W51] decayed slowly and quietly.
Region 11952 [S32E09] decayed slowly and quietly.
Region 11953 [S17W51] decayed slowly and was mostly quiet.
Region 11954 [N07W28] was quiet and stable.
New region 11955 [S13E62] rotated into view on January 15 and was numbered the next day by SWPC.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3011 [S15W13] was quiet and stable.
S3021 [S14E50] developed slowly and quietly.
New region S3029 [S22E77] rotated into view with a penumbra spot. Either this region or one just behind it at the southeast limb was the source of a C6.2 flare at 21:39 UTC.

Coronal mass ejections (CMEs)

January 14-16: 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

No obvious coronal holes are currently in or near Earth facing positions.

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 17-20.

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
11948 2014.01.05
2014.01.06
2 2 2 N05W68 0050 HAX HAX  
11949 2014.01.07
2014.01.08
2 7 4 S17W34 0110 HAX CSO area: 0200
11954 2014.01.08
2014.01.14
  2 1 N07W30 0008   AXX  
11951 2014.01.09
2014.01.10
      S12W70           plage
11953 2014.01.09
2014.01.11
7 13 6 S17W53 0030 DAO CAO area: 0060
11950 2014.01.09
2014.01.10
2 2 1 N16W51 0010 AXX BXO area: 0006
11952 2014.01.10
2014.01.11
3 9 3 S31E13 0060 CSO CSO

location: S32E09

S3009 2014.01.10       N10W46           plage
S3011 2014.01.11   4 3 S15W13 0013   AXX  
S3012 2014.01.12       N10W16           plage
S3014 2014.01.12       S07W46         plage
S3017 2014.01.13       S30E06           plage
S3018 2014.01.13       N07W55           plage
S3021 2014.01.14   7 3 S14E50 0022   CRO  
S3022 2014.01.14       S13W00           plage
S3023 2014.01.14       S26W41           plage
S3024 2014.01.14       N15E05         plage
11955 2014.01.15
2014.01.16
1 2 1 S14E54 0070 HSX CSO area: 0140

location: S13E62

S3027 2014.01.15       S27W02         plage
S3028 2014.01.15       N22E01         plage
S3029 2014.01.16   1   S22E77 0003   AXX    
Total spot count: 17 49 24  
Sunspot number: 77 149 114  (total spot count + 10 * number of spotted regions)
Weighted SN: 42 77 52  (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): 46 52 63 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
2014.01 171.2 (1) 73.2 (2A) / 141.9 (2B) / 99.6 (2C) (67.6 projected, +0.2) (6.4)

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.