Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 3, 2014 at 05:40 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 December 16, 2013]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet to active on January 2. Solar wind speed at SOHO ranged between 525 and 605 km/s under the influence of a high speed stream from CH598.

Solar flux measured at 20h UTC on 2.8 GHz was 160.5 (increasing 10.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 141.4. The Potsdam WDC planetary A index was 19 (STAR Ap - based on the mean of three hour interval ap indices: 18.8). Three hour interval K indices: 34433342 (planetary), 34424343 (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 12 active regions in 2K resolution (SN: 299) and 11 active regions in 1K resolution (SN: 204) SDO images on the visible solar disk.

Region 11936 [S16W66] was quiet and stable.
Region 11937 [S14W27] was quiet and stable.
Region 11938 [S15W15] gained several penumbra spots.
Region 11940 [S11W72] developed slowly and was quiet. C flares are possible.
Region 11941 [S13W47] decayed slowly and quietly.
Region 11942 [N09E38] was quiet and stable.
Region 11943 [S12E46] was quiet and stable.
Region 11944 [S08E63] is a large and complex region capable of producing major M and X class flares. There is a magnetic delta structure in the northern part of the largest penumbra.
C5+ flares: long duration M1.7 peaking at 02:33, C5.3 at 04:29, C9.5 at 12:26, M1.2/1N at 22:18 UTC.
New region 11945 [N10E18] emerged on January 1 and was numbered the next day by SWPC.

Spotted regions not numbered (or interpreted differently) by SWPC:
S2966 [S14E07] reemerged with penumbra spots.
S2971 [S20E18] rwas quiet and stable.
S2975 [S24W37] reemerged with penumbra spots.

Coronal mass ejections (CMEs)

December 31 - January 2: 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 recurrent trans equatorial coronal hole (CH598) was in an Earth facing position on December 29-31.

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 to good.

Forecast

The geomagnetic field is expected to be quiet to active on January 3 due to effects from CH598 and quiet to unsettled on January 4-5.

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
11936 2013.12.22
2013.12.23
9 17 12 S17W62 0160 EAI ESI beta-gamma

area: 0330

location: S16W66

S2947 2013.12.24       S21W40           plage
S2949 2013.12.24       N07W42           plage
11937 2013.12.25
2013.12.26
  4 2 S12W37 0017   BXO location: S14W27
11938 2013.12.26
2013.12.27
4 28 18 S14W16 0030 CAO CRI area: 0060
S2959 2013.12.27       N18W14         plage
11941 2013.12.28
2013.12.31
4 18 8 S13W48 0030 DAO DRI area: 0060
S2965 2013.12.29       S28W10           plage
S2966 2013.12.29   3 1 S14E07 0010   BXO   plage
S2967 2013.12.29       S35W36           plage
S2968 2013.12.29       N23W59           plage
S2971 2013.12.30   1   S20E18 0002   AXX  
11943 2013.12.30
2013.12.31
2 11 3 S11E45 0020 CRO CRO area: 0045
11942 2013.12.30
2013.12.31
4 10 6 N10E37 0030 CAO DSO area: 0080
11940 2013.12.30
2013.12.31
7 21 10 S12W73 0070 DAO DKC area: 0330
S2975 2013.12.30   3 2 S24W37     BXO    
11944 2013.12.31
2014.01.01
19 55 27 S08E64 0250 FKC FKC beta-gamma-delta

area: 1900

S2977 2013.12.31       N14W03         plage
11945 2014.01.01
2014.01.02
4 8 5 N10E18 0010 BXO DRO area: 0060
S2980 2014.01.01       S04E07         plage
Total spot count: 53 179 94  
Sunspot number: 133 299 204  (total spot count + 10 * number of spotted regions)
Weighted SN: 91 221 136  (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): 80 105 112 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) 4.6
2014.01 160.1 (1) 7.7 (2A) / 119.5 (2B) / 93.8 (2C) (67.6 projected, +0.2) (15.4)

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.