Solar Terrestrial Activity Report

Activity chart

Last major update issued on December 5, 2014 at 05:55 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 active on December 4. Solar wind speed at SOHO ranged between 455 and 556 km/s.

Solar flux at 18h UTC on 2.8 GHz was 151.9 (increasing 19.9 over the last solar rotation, the measurement at 20h UTC was discarded as it was flare enhanced). The 90 day 10.7 flux at 1 AU was 151.7 - the highest since May 2, 2014). The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.5). Three hour interval K indices: 21112324 (planetary), 22212333 (Boulder).

The background x-ray flux is at the class B5 level.

At the time of counting spots (see image time), spots were observed in 13 active regions using 2K resolution (SN: 212) and 11 active regions using 1K resolution (SN: 158) SDO images on the visible solar disk.

Region 12217 [S15W80] decayed slowly and quietly.
Region 12218 [N17W63] was quiet and stable.
Region 12221 [N07W37] decayed slowly and quietly.
Region 12222 [S19W37] lost spots. Two magnetic deltas formed at the eastern edge of the largest penumbra and caused the region to become more unstable. Further M class flares are possible.
Region 12225 [S15E10] was quiet and decayed slowly.
Region 12226 [S19W61] decayed slowly and was mostly quiet.
Region 12227 [S03E47] was quiet and stable.
New region 12228 [N09W16] emerged on December 3 and was numbered the next day when the region was decaying slowly.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4047 [N14E28] was quiet and stable.
S4048 [N09E39] reemerged with penumbra spots.
S4053 [S13W03] was quiet and stable.
New region S4056 [S22E48] emerged with penumbra spots.
New region S4057 [S14E38] emerged with a penumbra spot.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
M1.3/1N 08:10 S24W27 12222  
C5.4/1F 08:56 S25W27 12222  
M6.1 18:25   12222  
M1.3 19:41   12222  

Coronal mass ejections (CMEs)

December 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]

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 fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on December 5-7.

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
12217 2014.11.22
2014.11.23
3 2 2 S15W82 0030 DAO AXX

area: 0015

12218 2014.11.23 1 2 1 N17W63 0140 HSX CSO

 

12221 2014.11.25
2014.11.26
6 6 2 N05W40 0020 CRO BXO  
12222 2014.11.26 32 38 21 S19W37 0770 EKC EKC beta-gamma-delta
12224 2014.11.26
2014.11.28
      S24W55         plage
12226 2014.11.27
2014.12.01
4 5 4 S19W61 0030 CRO DRO

 

S4042 2014.11.27       S05W51         plage
12225 2014.11.29
2014.11.30
7 10 9 S15E05 0010 BXO DRO location: S15E10

area: 0030

12227 2014.12.02 1 2 1 S04E45 0080 HSX CSO location: S03E47

area: 0180

S4047 2014.12.02   5 2 N14E28 0010   AXX  
S4048 2014.12.02   2 1 N09E39 0004   BXO    
S4049 2014.12.02       S09W14           plage
12228 2014.12.03
2014.12.04
3 6 4 N09W16 0010 BXO BXO area: 0020
S4053 2014.12.03   1   S13W03 0002   AXX  
S4054 2014.12.03       S06E63         plage
S4056 2014.12.04   2   S22E48 0005   BXO    
S4057 2014.12.04   1 1 S14E38 0004   AXX    
Total spot count: 57 82 48  
Sunspot number: 137 212 158  (total spot count + 10 * number of spotted regions)
Weighted SN: 88 108 74  (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): 82 74 87 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
2014.12 160.5 (1)   18.4 (2A) / 142.8 (2B) / 91.9 (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.