Solar Terrestrial Activity Report

Activity chart

Last major update issued on December 1, 2014 at 05:35 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 November 1, 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 November 30. Solar wind speed at SOHO ranged between 357 and 472 km/s.

Solar flux at 18h UTC on 2.8 GHz was 177.3 (increasing 52.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 151.1 - the highest since May 3, 2014). The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 6.8). Three hour interval K indices: 12211322 (planetary), 11222332 (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 15 active regions using 2K resolution (SN: 333) and 14 active regions using 1K resolution (SN: 243) SDO images on the visible solar disk.

Region 12216 [S13W65] decayed slowly and quietly.
Region 12217 [S17W25] decayed in the trailing spot section while new spots emerged in the leading polarity area. The region has polarity intermixing and a minor M class flare is possible.
Region 12218 [N17W09] was quiet and stable.
Region 12219 [N03W61] decayed significantly and lost the magnetic delta.
Region 12220 [S16W52] decayed slowly and quietly.
Region 12221 [N05E16] decayed slowly and quietly.
Region 12222 [S19E15] lost the magnetic delta but remains capable of producing an M class flare.
Region 12223 [N15W52] developed slowly and quietly.
Region 12224 [S22E09] decayed slowly and quietly.
New region 12225 [S15E59] rotated into view on November 29 and was numbered by SWPC the next day.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4020 [N14W17] was quiet and stable.
S4039 [S19W07] reemerged with several spots.
S4042 [S04E02] was quiet and stable.
S4043 [N13W75] decayed slowly and quietly.
New region S4045 [N24W09] was observed with a penumbra spot.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C2.1 17:19 N05E28 12221  

Coronal mass ejections (CMEs)

November 28-30: 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 fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be mostly quiet on December 1-3. The background proton flux has increased slowly at ACE and in a way that is similar to what is expected from an approaching CME. If there is a CME on its way it will likely arrive on December 1.

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
12216 2014.11.19
2014.11.20
8 11 5 S14W65 0160 DAO CAO  
12217 2014.11.22
2014.11.23
9 31 16 S18W25 0080 DAO DAI beta-gamma
S4016 2014.11.22       N12W57           plage
S4020 2014.11.23   3 2 N14W17 0010   AXX  
12218 2014.11.23 1 6 4 N16W11 0140 HSX CSO

area: 0230

12219 2014.11.24 9 13 8 N04W60 0300 DKO DKO  
12220 2014.11.24   1   S16W55 0002 AXX AXX  
S4028 2014.11.24       S05W34           plage
12221 2014.11.25
2014.11.26
14 33 21 N04E16 0160 DSI DAI  
S4033 2014.11.25       S08W52           plage
12222 2014.11.26 30 43 26 S20E17 0680 EKC EKI beta-gamma-delta

area: 0870

12224 2014.11.26
2014.11.28
  4 2 S24E01 0010   BXO location: S22E09
12223 2014.11.26
2014.11.27
1 7 4 N16W52 0010 AXX DRO

reversed polarities

area: 0020

S4037 2014.11.26       N12W28           plage
S4038 2014.11.26       S27W53         plage
S4039 2014.11.27   16 8 S19W07 0080   DRI    
S4041 2014.11.27       N26W21           plage
S4042 2014.11.27   5 3 S04E02 0010   BXO  
S4043 2014.11.28   2 1 N13W75 0010   HRX  
12225 2014.11.29
2014.11.30
1 7 2 S17E56 0010 AXX CRO location: S15E59

area: 0020

S4045 2014.11.30   1 1 N24W09 0003   AXX    
Total spot count: 73 183 103  
Sunspot number: 153 333 243  (total spot count + 10 * number of spotted regions)
Weighted SN: 113 235 155  (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): 92 117 134 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 (1)   101.9 (2A/2B) / 90.8 (2C) (66.0 projected, -1.7) ()

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.