Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 5, 2015 at 05:00 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 4. Solar wind speed at SOHO ranged between 358 and 460 km/s under the influence of a corotating interaction region.

Solar flux at 20h UTC on 2.8 GHz was 149.7 (increasing 17.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 153.2. The Potsdam WDC planetary A index was 17 (STAR Ap - based on the mean of three hour interval ap indices: 16.8). Three hour interval K indices: 11233534 (planetary), 01344534 (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 8 active regions using 2K resolution (SN: 178) and 7 active regions using 1K resolution (SN: 120) SDO images on the visible solar disk.

Region 12248 [S19W80] decayed slowly and quietly.
Region 12251 [S14W48] decayed slowly and quietly.
Region 12252 [S20W25] decayed slowly and quietly.
Region 12253 [S07W05] decayed further and lost the magnetic delta structure.
Region 12255 [S15E38] was mostly quiet and stable.
Region 12256 [S07W78] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4123 [S15W09] reemerged with penumbra spots.
New region S4128 [S19E02] emerged with a penumbra spot.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C2.1 04:52   12253  
M1.3/2N (LDE) 15:31 S07E02 12253  

Coronal mass ejections (CMEs)

January 2-4: 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 small trans equatorial coronal hole (CH648) was in an Earth facing position on January 2. A recurrent northern hemisphere coronal hole (CH649) could rotate into an Earth facing position on January 6-8.

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 active on January 5-7 due to coronal hole effects.

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
12248 2014.12.23 1 1 1 S19W82 0020 HAX HRX

 

S4105 2014.12.25       S10W59           plage
12251 2014.12.26 5 9 4 S13W48 0100 DSO DAO

 

12252 2014.12.27 2 4 3 S20W27 0050 HAX CAO  
S4112 2014.12.27       N03W59           plage
12253 2014.12.29
2014.12.30
42 54 29 S07W04 0860 EKC FKC beta-gamma
S4114 2014.12.29       N20W21         plage
S4118 2014.12.30       S15W31           plage
12254 2014.12.31       S22W49           plage
12256 2014.12.31
2015.01.02
5 3 1 S08W74 0030 CAO CAO area: 0100
12255 2015.01.01 9 23 11 S16E38 0160 DAI DAI beta-gamma

area: 0200

S4123 2015.01.01   3 1 S15W09 0006   BXO    
S4124 2015.01.02       N04E23           plage
S4125 2015.01.02       S17W34           plage
S4127 2015.01.03       N06E40         plage
S4128 2015.01.04   1   S19E02 0002   AXX  

 

Total spot count: 64 98 50  
Sunspot number: 124 178 120  (total spot count + 10 * number of spotted regions)
Weighted SN: 99 131 83  (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): 74 62 66 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)   14.9 (2A) / 115.3 (2B) / 87.9 (2C) (66.5 projected, -1.2) (11.6)

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.