Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 6, 2015 at 04:35 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, 2015)] [Cycle 24 progress (last update January 1, 2015) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update January 1, 2015)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update January 1, 2015)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update January 3, 2015)]

[Noon SDO sunspot count 1K Reference: 4K (large file) (updated daily)]

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated December 27, 2014]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to minor storm on January 5. Solar wind speed at SOHO ranged between 415 and 554 km/s under the influence of a high speed stream from CH648.

Solar flux at 20h UTC on 2.8 GHz was 141.9 (increasing 2.2 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 153.3. The Potsdam WDC planetary A index was 15 (STAR Ap - based on the mean of three hour interval ap indices: 14.8). Three hour interval K indices: 53222223 (planetary), 42222223 (Boulder).

The background x-ray flux is at the class B7 level.

At the time of counting spots (see image time), spots were observed in 6 active regions using 2K resolution (SN: 169) and 5 active regions using 1K resolution (SN: 104) SDO images on the visible solar disk.

Region 12251 [S15W62] was quiet and stable.
Region 12252 [S20W39] decayed slowly and quietly.
Region 12253 [S07W18] decayed slowly with the major penumbrae fragmenting into smaller penumbrae. A magnetic delta structure formed in a trailing penumbra early in the day and caused increased flare activity. By the end of the day the delta had weakened.
Region 12255 [S15E26] decayed slowly and quietly.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4127 [N04E23] reemerged with a penumbra spot.
New region S4130 [S08W50] emerged with penumbra spots.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C2.0 02:09 S07W07 12253  
C3.5 08:22 S09W02 12253  
C3.9 14:59 SE limb    
C7.4/2F (LDE) 17:44 S07W12 12253  
C4.1/1F (LDE) 22:12 S06W15 12253  
C4.4 23:20 NE limb   attributed to AR 12251 by SWPC

Coronal mass ejections (CMEs)

January 3-5: No obviously Earth directed CMEs were observed in LASCO 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 northern hemisphere coronal hole (CH649) could rotate into an Earth facing position on January 7-9.

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 to fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on January 6-7 due to coronal hole effects and quiet on January 8.

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: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% 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 Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12251 2014.12.26 3 8 4 S13W60 0070 DAO DAO

 

12252 2014.12.27 1 4 1 S19W41 0010 HAX CRO  
12253 2014.12.29
2014.12.30
26 67 36 S07W18 0700 FKC FAC beta-gamma-delta
S4114 2014.12.29       N20W34           plage
S4118 2014.12.30       S15W44           plage
12254 2014.12.31       S22W63           plage
12256 2014.12.31
2015.01.02
1     S06W90 0060 CAO     rotated out of view
12255 2015.01.01 8 24 10 S16E24 0080 DAI DAI beta-gamma
S4123 2015.01.01       S15W22         plage
S4124 2015.01.02       N04E10           plage
S4125 2015.01.02       S17W47           plage
S4127 2015.01.03   1   N04E23 0001   AXX    
S4128 2015.01.04       S19W11         plage
S4130 2015.01.05   5 3 S08W50     BXO  

 

Total spot count: 39 109 54  
Sunspot number: 89 169 104  (total spot count + 10 * number of spotted regions)
Weighted SN: 69 127 72  (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): 53 59 57 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for MSN 2K, k = 0.55 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number Average ap
(3)
Measured 1 AU
2013.09 102.6 103.7 36.9 73.1 (+4.1) 5.23
2013.10  132.1 131.2 85.6 75.0 (+1.9) 7.71
2013.11  148.3 145.1 77.6 75.4 (+0.4) 5.68
2013.12 147.7 143.1 90.3 76.0 (+0.6) 4.68
2014.01 157.4 152.4 81.8 77.3 (+1.3) 5.44
2014.02 170.3
(cycle peak)
166.3 102.3 (cycle peak) 78.4 (+1.1) 10.70
2014.03 149.9 148.5 91.9 80.8 (+2.4) 4.88
2014.04 143.9 144.8 84.7 81.9 (+1.1)
(likely solar max)
7.88
2014.05 129.7 132.9 75.2 80.5 (-1.4) 5.75
2014.06 122.0 125.8 71.0 79.7 (-0.8) 6.72
2014.07 137.4 141.8 72.5 (78.6 projected, -1.1) 4.50
2014.08 124.7 127.9 74.7 (76.2 projected, -2.4) 7.71
2014.09 146.6 148.1 87.6 (73.0 projected, -3.2) 9.78
2014.10 153.4 152.9 60.6 (70.5 projected, -2.5) 8.96
2014.11 154.8 151.4 70.1 (68.8 projected, -1.7) 9.33
2014.12 158.7 153.8 78.0 (67.7 projected, -1.1) 10.8
2015.01 145.2 (1)   17.7 (2A) / 110.0 (2B) / 87.9 (2C) (66.5 projected, -1.2) (12.3)

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 WDC-SILSO 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 GFZ 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.