Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 14, 2014 at 05:45 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 13. Solar wind speed at SOHO ranged between 524 and 763 km/s under the influence of a high speed stream from CH599.

Solar flux at 20h UTC on 2.8 GHz was 143.3 (decreasing 15.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 148.8. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.4). Three hour interval K indices: 23211112 (planetary), 22211211 (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 15 active regions in 2K resolution (SN: 252) and 13 active regions in 1K resolution (SN: 183) SDO images on the visible solar disk.

Region 11944 [S10W82] rotated to the southwest limb and still has the potential to produce a major flare. C5+ flare: impulsive M1.3 at 21:51 UTC.
Region 11946 [N08W82] decayed further with only a penumbra spot visible near the northwest limb.
Region 11948 [N05W27] decayed slowly and quietly.
Region 11949 [S17E07] was quiet and stable.
Region 11950 [N16W10] decayed in the trailing spot section and gained leading polarity penumbra spots.
Region 11952 [S32E49] decayed slowly and quietly.
Region 11953 [S18W12] became a compact region and there's a chance of C flares.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3001 [N07E13] was quiet and stable.
S3009 [N10W07] was quiet and stable.
S3011 [S15E26] was quiet and stable.
S3013 [N10W32] was quiet and stable.
S3014 [S08W03] was quiet and stable.
New region S3017 [S30E47] emerged very close to the leader spot in AR 11952. The proximity of the regions could cause flare activity.
New region S3018 [N07W16] emerged with penumbra spots.
New region S3019 [S13W27] emerged with penumbra spots.

A filament eruption was observed in the northeast quadrant from 10h UTC. The associated CME does not appear to have any Earth directed extensions.

Coronal mass ejections (CMEs)

January 11-13: 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 trans equatorial coronal hole (CH599) was in an Earth facing position on January 9-10.

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

Forecast

The geomagnetic field is expected to be quiet to active on January 14 due to effects from CH599. Quiet conditions are likely on January 15-17.

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
11944 2013.12.31
2014.01.01
18 16 6 S10W83 0830 FKC FKC beta-gamma

area: 1080

11946 2014.01.04 5 1   N08W87 0090 DAO AXX

area: 0004

11948 2014.01.05
2014.01.06
1 2 1 N08W31 0090 HAX HSX area: 0140

location: N05W27

S2995 2014.01.05       S18W42         images/AR_S2995_20140112_2345.png  
11949 2014.01.07
2014.01.08
3 13 6 S16E03 0160 HAX CSO area: 0230

location: S17E07

S3001 2014.01.08   11 6 N07E13 0035   BXO  
S3002 2014.01.08       N10W46           plage
S3003 2014.01.08       N19W56           plage
11951 2014.01.09
2014.01.10
  3 2 S12W28 0010   AXX  
11953 2014.01.09
2014.01.11
9 17 11 S18W13 0060 DAO DAC area: 0140
11950 2014.01.09
2014.01.10
  10 6 N17W12 0030   BXO location: N16W10
11952 2014.01.10
2014.01.11
6 11 6 S31E46 0120 CSO EAO

location: S32E49

S3009 2014.01.10   2 2 N10W07 0008   BXO  
S3010 2014.01.10       S32W21           plage
S3011 2014.01.11   1 1 S15E26 0004   AXX  
S3012 2014.01.12       N09E25         plage
S3013 2014.01.12   4 2 N10W32 0020   AXX  
S3014 2014.01.12   2   S08W03 0004   BXO  
S3015 2014.01.12       N15W27         plage
S3017 2014.01.13   6 3 S30E47 0030   CRO    
S3018 2014.01.13   3 1 N07W16 0010   BXO    
Total spot count: 42 102 53  
Sunspot number: 102 252 183  (total spot count + 10 * number of spotted regions)
Weighted SN: 75 135 88  (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 88 101 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
2014.01 181.2 (1) 64.9 (2A) / 154.7 (2B) / 101.3 (2C) (67.6 projected, +0.2) (6.8)

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.