Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 10, 2014 at 05:15 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 December 16, 2013]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet to unsettled on January 9. Solar wind speed at SOHO ranged between 347 and 489 km/s. A fairly weak solar wind shock was observed at SOHO at 19:33 UTC, likely the arrival of the CME observed on January 7. The CME arrived later than expected and with a weaker magnetic field than is normal for CMEs associated with X class flares.

Solar flux at 20h UTC on 2.8 GHz was 184.1 (increasing 21.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 147.6. The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.3). Three hour interval K indices: 33121022 (planetary), 22222232 (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 11 active regions in 2K resolution (SN: 318) and 11 active regions in 1K resolution (SN: 235) SDO images on the visible solar disk.

Region 11943 [S15W39] was quiet and stable.
Region 11944 [S10W28] decayed slowly and was mostly quiet. A major flare is still possible.

Region 11946 [N08W29] was quiet and stable.
Region 11948 [N06E27] was quiet and stable.
Region 11949 [S15E58] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S2995 [S15W02] was quiet and stable.
S3001 [N07E69] gained penumbra spots.
S3002 [N09E05] was quiet and stable.
New region S3005 [S13E26] emerged with several spots.
New region S3006 [S18E42] emerged with penumbra spots.
New region S3007 [N16E46] emerged with several spots.

Coronal mass ejections (CMEs)

January 8-9: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
January 7: A full halo CME was observed after the X1 event in AR 11943. The CME reached Earth during the evening of January 9.

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) will rotate into 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 poor.

Forecast

The geomagnetic field is expected to be quiet to unsettled due to weak CME effects on January 10 and quiet on January 11. A high speed stream from CH599 could cause quiet to active conditions on January 12-13.

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
11943 2013.12.30
2013.12.31
  10 4 S11W49 0025   AXX

location: S15W39

11942 2013.12.30
2013.12.31
      N10W62         plage
11944 2013.12.31
2014.01.01
52 117 77 S09W28 1420 FKC FKC beta-gamma-delta

area: 1700

11945 2014.01.01
2014.01.02
      N11W80           plage
S2983 2014.01.03       N21W13           plage
11946 2014.01.04 12 40 24 N08W32 0300 DAI DKI

location: N08W29

area: 0380

S2988 2014.01.04       N20W44           plage
11948 2014.01.05
2014.01.06
1 7 3 N06E25 0090 HSX HSX area: 0160
S2992 2014.01.05       N17W17           plage
S2993 2014.01.05       N04W44           plage
S2995 2014.01.05   9 3 S15W02 0025   BXO  
S2996 2014.01.06       S01W26           plage
11949 2014.01.07
2014.01.08
1 1 1 S15E56 0150 HSX HHX area: 0250
S2999 2014.01.07       S32W17           plage
S3000 2014.01.07       S19W18           plage
S3001 2014.01.08   4 1 N07E69 0015   BXO  
S3002 2014.01.08   4 3 N09E05 0015   AXX  
S3003 2014.01.08       N19W04         plage
S3005 2014.01.09   9 4 S13E26 0030   DRO    
S3006 2014.01.09   2 1 S18E42 0006   AXX    
S3007 2014.01.09   5 4 N16E46 0050   DRO    
Total spot count: 66 208 125  
Sunspot number: 106 318 235  (total spot count + 10 * number of spotted regions)
Weighted SN: 91 249 166  (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): 64 111 129 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
2014.01 190.6 (1) 49.3 (2A) / 169.9 (2B) / 100.6 (2C) (67.6 projected, +0.2) (7.5)

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.