Solar Terrestrial Activity Report

Activity chart

Last major update issued on December 6, 2014 at 06:55 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update December 1, 2014)] [Cycle 24 progress (last update December 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update December 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update December 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update December 3, 2014)]

[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 November 22, 2014]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to unsettled on December 5. Solar wind speed at SOHO ranged between 436 and 475 km/s.

Solar flux at 20h UTC on 2.8 GHz was 136.8 (increasing 4.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 151.4. The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.4). Three hour interval K indices: 23223212 (planetary), 23233221 (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 15 active regions using 2K resolution (SN: 215) and 10 active regions using 1K resolution (SN: 125) SDO images on the visible solar disk.

Region 12218 [N17W76] was quiet and stable.
Region 12221 [N03W47] decayed slowly and quietly.
Region 12222 [S20W52] decayed slowly. There is still a weak magnetic delta east the southeastern edge of the large penumbra. An M class flare is possible.
Region 12225 [S16W00] decayed slowly and quietly.
Region 12226 [S19W73] decayed slowly and was mostly quiet.
Region 12227 [S03E34] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4042 [S03W66] reemerged with penumbra spots.
S4047 [N12E19] was quiet and stable.
S4048 [N07E26] was quiet and stable.
S4053 [S09W26] was quiet and stable.
S4056 [S23E37] developed slowly and quietly.
S4057 [S14E26] decayed slowly and quietly.
New region S4058 [S13E73] rotated into view.
New region S4059 [N11W48] emerged with a penumbra spot.
New region S4060 [S40W08] emerged with a penumbra spot at a high latitude.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C2.1/1F 05:37 S20W35 12222  
M1.5 12:25   12222 flare superimposed on LDE in AR 12217
C2.1 23:48   12222  

Coronal mass ejections (CMEs)

December 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]

No obvious coronal holes are currently in or near Earth facing positions.

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 December 6-8.

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
12218 2014.11.23 1 1 1 N17W77 0110 HSX HSX

area: 0190

12221 2014.11.25
2014.11.26
  2   N05W54 0004   AXX location: N03W47
12222 2014.11.26 23 26 10 S20W51 0560 EHI EKO beta-gamma-delta
12224 2014.11.26
2014.11.28
      S24W69           plage
12226 2014.11.27
2014.12.01
5 1 1 S19W75 0010 BXO HRX

 

S4042 2014.11.27   5   S03W66 0010   BXO    
12225 2014.11.29
2014.11.30
4 7 3 S15W08 0010 BXO AXX location: S16W00

area: 0020

12227 2014.12.02 1 5 2 S03E32 0120 HSX CSO

area: 0220

S4047 2014.12.02   6 1 N12E19 0010   BXO  
S4048 2014.12.02   1   N07E26 0002   AXX  
S4049 2014.12.02       S09W27           plage
12228 2014.12.03
2014.12.04
3     N08W31 0010 BXO     spotless
S4053 2014.12.03   2 1 S09W26 0005   AXX  
S4054 2014.12.03       S06E50           plage
S4056 2014.12.04   5 4 S23E37 0020   CRO  
S4057 2014.12.04   1   S14E26 0001   AXX  
S4058 2014.12.05   1 1 S13E73 0006   AXX    
S4059 2014.12.05   1 1 N11W48 0006   AXX    
S4060 2014.12.05   1   S40W08 0001   AXX    
Total spot count: 37 65 25  
Sunspot number: 97 215 125  (total spot count + 10 * number of spotted regions)
Weighted SN: 57 91 51  (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): 58 75 69 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
2013.08 114.6 118.3 66.0 69.0 (+3.5) 8.27
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 (79.1 projected, -1.6) 6.72
2014.07 137.4 141.8 72.5 (77.5 projected, -1.6) 4.50
2014.08 124.7 127.9 74.7 (75.1 projected, -3.0) 7.71
2014.09 146.6 148.1 87.6 (71.9 projected, -3.2) 9.78
2014.10 153.4 152.9 60.6 (69.5 projected, -2.4) 8.96
2014.11 154.8   70.1 (67.7 projected, -1.8) 8.9
2014.12 155.7 (1)   21.5 (2A) / 133.6 (2B) / 91.3 (2C) (66.0 projected, -1.7) (8.4)

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 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.