Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 3, 2015 at 07:20 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 active on January 2. Solar wind speed at SOHO ranged between 351 and 464 km/s. A disturbance, probably coronal hole related, began late in the day.

Solar flux at 20h UTC on 2.8 GHz was 145.8 (increasing 17.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 152.9. The Potsdam WDC planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 9.6). Three hour interval K indices: 31222234 (planetary), 31223323 (Boulder).

The background x-ray flux is at the class B6 level.

At the time of counting spots (see image time), spots were observed in 13 active regions using 2K resolution (SN: 266) and 11 active regions using 1K resolution (SN: 184) SDO images on the visible solar disk.

Region 12246 [N18W80] was quiet and stable.
Region 12248 [S19W53] decayed slowly and quietly.
Region 12251 [S14W20] developed slowly and quietly.
Region 12252 [S20W00] was quiet and stable.
Region 12253 [S07E23] gained penumbral area and spots. Although the region has been fairly quiet, there is a chance of an M class flare due to the magnetic delta in the leading penumbra.
Region 12254 [S22W19] was quiet and stable.
Region 12255 [S14E65] was quiet and stable.
New region 12256 [S08W47] emerged on December 31 and was numbered by SWPC 2 days later.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4114 [N18E01] was quiet and stable.
S4123 [S16E18] was quiet and stable.
New region S4124 [N04E49] was observed with penumbra spots.
New region S4125 [S17W08] emerged with penumbra spots.
New region S4126 [S05W44] emerged with penumbra spots.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
         

Coronal mass ejections (CMEs)

December 31 - January 2: 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 corotating interaction region could be associated with the large southern hemisphere coronal hole. In that case the coronal hole related to the CIR was in an Earth facing position on January 1-2.

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 active on January 3-7 due to coronal hole efects.

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
12246 2014.12.21 1 1 1 N19W83 0090 HSX HSX area: 0100

location: N18W80

12247 2014.12.23       S19W74          

real location: S25W72

12248 2014.12.23 1 4 2 S19W55 0050 HAX CAO

 

S4103 2014.12.24       N05W59           plage
S4105 2014.12.25       S10W46           plage
12251 2014.12.26 5 26 15 S12W21 0160 DSO DAI

area: 0220

12252 2014.12.27 1 6 4 S20W01 0060 HAX CAO area: 0130
S4112 2014.12.27       N03W33           plage
12253 2014.12.29
2014.12.30
22 68 33 S06E22 0770 EKC EKC beta-gamma-delta

area: 1200

S4114 2014.12.29   3 2 N18E01 0012   AXX  
S4115 2014.12.29       N07W39           plage
S4117 2014.12.29       S09W42           plage
S4118 2014.12.30       S15W05           plage
12254 2014.12.31 1 5 3 S22W21 0010 AXX CRO  
12256 2014.12.31
2015.01.02
1 14 11 S08W47 0020 CRO DRI area: 0050
S4121 2014.12.31       N08W52           plage
12255 2015.01.01 1 1 1 S14E63 0090 HSX HSX area: 0130
S4123 2015.01.01   2   S16E18 0004   AXX  
S4124 2015.01.02   2   N04E49 0004   AXX    
S4125 2015.01.02   2 1 S17W08 0005   BXO    
S4126 2015.01.02   2 1 S05W44 0006   BXO  

 

Total spot count: 33 136 74  
Sunspot number: 113 266 184  (total spot count + 10 * number of spotted regions)
Weighted SN: 71 177 115  (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): 68 93 101 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
2015.01 141.2 (1)   6.9 (2A) / 107.0 (2B) / 88.5 (2C) (66.5 projected, -1.2) (7.9)

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.