Solar Terrestrial Activity Report

Activity chart

Last major update issued on December 13, 2015 at 06:10 UT.

Charts (* = updated daily) Data and archive
  Solar wind (*) Solar and geomagnetic data - last month (*)
  Electron fluence (*) Archived daily reports and monthly data from 2003.01 (December 3, 2015)
Solar cycle Solar cycles 23-24 (December 1, 2015) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24 progress (December 1, 2015) Noon SDO sunspot count 1K Reference: 4K (large file) (*)
  Solar cycles 1-24 (July 17, 2015) POES auroral activity level October 2009 - December 2012
  Comparison of cycles 21, 22, 23 and 24 (December 1, 2015) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12, 13, 14, 16 and 24 (December 1, 2015) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (November 16, 2015)  

Recent activity

The geomagnetic field was quiet to unsettled on December 12, decreasingly under the influence of a high speed stream from CH704. Solar wind speed at SOHO ranged between 469 and 598 km/s.

Solar flux at 20h UTC on 2.8 GHz was 116.7 (increasing 10.9 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 105.9. The Potsdam WDC planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 9.1). Three hour interval K indices: 23312222 (planetary), 24332222 (Boulder).

The background x-ray flux is at the class B4 level.

At the time of counting spots (see image time), spots were observed in 13 active regions using 2K resolution (SN: 200) and 9 active regions using 1K resolution (SN: 113) SDO images on the visible solar disk.

Region 12462 [N08W45] was quiet and stable.
Region 12463 [S09W48] decayed slowly and quietly.
Region 12464 [S10W24] decayed slowly and quietly.
Region 12465 [S06W03] decayed slowly and quietly.
Region 12466 [S15W33] decayed slowly and was mostly quiet.
Region 12468 [S15E40] decayed and became magnetically less complex.
New region 12469 [N18E70] rotated into view on December 11 and was numbered by SWPC the next day.
New region 12470 [N12E80] rotated into view before noon and has a large leader spot. The region produced the majority of the flares during the day and M class flaring is possible.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4956 [N10E38] was quiet and stable.
S4959 [N08W23] gained a few tiny spots.
New region S4963 [N14E04] emerged near CH705 with a tiny spot.
New region S4964 [N23E27] was observed with a tiny spot.
New region S4965 [S22E23] was observed with tiny spots.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
C2.0 03:16 N18E80 12469 GOES15 incorrectly attributed to AR 12465 by SWPC
C2.6 (LDE) 04:31   12466 SDO/EVE  
C5.2 05:28 N12E90 12470 GOES15 incorrectly attributed to AR 12468 by SWPC
C4.2 06:13 N12E90 12470 GOES15 incorrectly attributed to AR 12469 by SWPC
C2.1 11:45 N12E90 12470 GOES15 incorrectly attributed to AR 12468 by SWPC
C7.8 13:46 N12E90 12470 GOES15  
C2.8 18:17 N12E90 12470 GOES15 incorrectly attributed to AR 12469 by SWPC

Flare activity (SDO/EVE/ESP XRS-B proxy)

Coronal mass ejections (CMEs)

December 10-12: No obviously Earth directed CMEs were observed in available 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 recurrent northern hemisphere coronal hole (CH705) will rotate across the central meridian on December 11-13.

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 13. Quiet to active is likely on December 14-15 due to effects from CH705.

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). 4K resolution. Compare to the previous day's image.
As of December 12, 2015, the active region maps are based on image products from semi-automated sunspot counting at 4K resolution.

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 overlays
Comment
SWPC Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12462 2015.12.02
2015.12.03
  1   N10W52 0001   AXX

location: N08W45

12463 2015.12.03 3 5 2 S09W48 0020 CRO HRX

 

12466 2015.12.04
2015.12.08
1 4 1 S13W35 0010 AXX CRO  

area: 0015

12464 2015.12.04
2015.12.05
3 5 3 S09W23 0010 BXO BXO  
S4942 2015.12.05       N15W54            
12465 2015.12.06
2015.12.07
3 16 6 S06W03 0030 HAX CRO beta-gamma
S4945 2015.12.06       N10W23            
12467 2015.12.08
2015.12.09
      S05W30          
12468 2015.12.09
2015.12.10
5 13 5 S15E39 0040 DAO CAO

 

S4953 2015.12.10       S01W08            
S4955 2015.12.10       S22W58            
S4956 2015.12.11   8   N10E38 0015   BXO  
12469 2015.12.11
2015.12.12
3 5 2 N18E67 0100 DSO DAO area: 0140

location: N18E70

S4958 2015.12.11       S25W33          
S4959 2015.12.11   4 1 N08W23 0009   BXO  
S4960 2015.12.11       S18W04          
12470 2015.12.12 1 5 2 N13E76 0080 HSX DKO   area: 0500

location: N12E80

S4963 2015.12.12   1 1 N14E04 0002   AXX    
S4964 2015.12.12   1   N23E27 0001   AXX    
S4965 2015.12.12   2   S22E23 0002   AXX    
Total spot count: 19 70 23  
Sunspot number: 89 200 113  (total spot count + 10 * number of spotted regions)
Weighted SN: 42 99 52  (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): 98 110 96 k * (sunspot number)
As of July 1, 2015: k = 1.1 for SWPC, k = 0.55 for MSN 2K, k = 0.85 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO) (4)
Smoothed sunspot number (4) Average ap
(3)
Measured 1 AU
2014.02 170.3
(cycle peak)
166.3 146.1 (cycle peak) 110.5 (+1.2) 10.70
2014.04 143.9 144.8 112.5 116.4 (+2.1) (solar max) 7.88
2014.10 153.4 152.9 90.0 97.3 (-4.6) 8.96
2014.11 154.8 151.4 103.6 94.7 (-2.6) 9.33
2014.12 158.7 153.8 112.9 92.2 (-2.5) 11.24
2015.01 141.9 137.3 93.0 89.3 (-2.9) 9.46
2015.02 129.1 126.0 66.7 86.1 (-3.2) 9.92
2015.03 125.9 124.6 54.5 82.2 (-3.9) 16.14
2015.04 128.8 129.7 75.3 78.9 (-3.3) 10.73
2015.05 120.0 122.6 88.8 76.0 (-2.9) 8.29
2015.06 122.3 126.1 66.5 (72.1 projected, -3.9) 13.15
2015.07 107.0 110.8 66.4 (68.4 projected, -3.7) 8.83
2015.08 105.4 108.0 64.6 (67.2 projected, -1.2) 14.58
2015.09 101.7 102.7 78.1 (67.4 projected, +0.2) 15.78
2015.10 104.1 103.3 61.7 (66.5 projected, -0.9) 14.02
2015.11 109.3 106.9 63.2 (64.5 projected, -2.0) 12.09
2015.12 (103.2)   20.7 (2A) / 53.4 (2B) / 73.1 (2C) (62.7 projected, -1.8) (11.7)

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).
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.
4) Updated to new data set from WDC-SILSO on July 1, 2015

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 Universal Time. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.