Solar Terrestrial Activity Report

Activity chart

Last major update issued on January 5, 2016 at 04:20 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 (January 1, 2016)
Solar cycle Solar cycles 23-24 (January 1, 2016) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24 progress (January 1, 2016) 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 (January 1, 2016) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12, 13, 14, 16 and 24 (January 1, 2016) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (December 27, 2015)  

Recent activity

The geomagnetic field was quiet on January 4. Solar wind speed at SOHO ranged between 377 and 456 km/s.

Solar flux at 20h UTC on 2.8 GHz was 95.3 (decreasing 10.4 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 106.6. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.9). Three hour interval K indices: 01110211 (planetary), 11201221 (Boulder).

The background x-ray flux is at the class B2 level.

At the time of counting spots (see image time), spots were observed in 8 active regions using 2K resolution (SN: 120) and 5 active regions using 1K resolution (SN: 64) SDO images on the visible solar disk.

Region 12476 [S09E21] decayed slowly and quietly.
Region 12477 [N12E35] was quiet and stable.
Region 12478 [N07E27] decayed and could soon become spotless.
New region 12479 [N13E08] emerged on January 1 and was numbered 3 days later by SWPC. The region decayed quickly on January 4.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4997 [S05E45] was quiet and stable.
S5000 [N12W23] was quiet and stable.
S5002 [S10W00] was quiet and stable.
New region S5004 [S21E22] was observed with a tiny spot.

C2+ flares:

Magnitude Peak time (UT) Location AR Recorded by Comment
           

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

Coronal mass ejections (CMEs)

January 3-4: No obviously Earth directed CMEs were observed in available LASCO imagery.
January 2: A fast CME was observed after the M2 LDE in AR 12473 early in the day. The CME did not reach Earth.

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 trans equatorial coronal hole (CH708) rotated across the central meridian on January 2-3.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle latitudes is poor and slowly improving. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be initially quiet on January 5. During the latter half of the day a high speed stream associated with CH708 is likely to arrive and cause quiet to active conditions until January 7, minor storm intervals are possible on January 5-6.

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
12476 2015.12.31
2016.01.01
12 20 9 S10E20 0070 DAO DRI

location: S09E21

12477 2016.01.01 1 3 1 N12E33 0070 HSX HSX area: 0110
12479 2016.01.01
2016.01.04
4 2 1 N11E05 0010 BXO CRO  
S4997 2016.01.01   5   S05E45 0010   BXO  
S4998 2016.01.01       S25W27            
12478 2016.01.02 3 3 1 N07E24 0010 BXO BXO  
S5000 2016.01.02   2   N12W23 0006   BXO images/AR_S5000_20160103_2345.png  
S5002 2016.01.02   4 2 S10W00 0008   AXX  
S5004 2016.01.04   1   S21E22 0001   AXX    
Total spot count: 20 40 14  
Sunspot number: 60 120 64  (total spot count + 10 * number of spotted regions)
Weighted SN: 30 51 25  (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): 66 66 54 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
2014.11 154.8 151.4 103.6 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 78.8 (-3.4) 10.73
2015.05 120.0 122.6 88.8 76.0 (-2.8) 8.29
2015.06 122.3 126.1 66.5 72.0 (-4.0) 13.15
2015.07 107.0 110.8 66.4 (68.3 projected, -3.7) 8.83
2015.08 105.4 108.0 64.6 (66.3 projected, -2.0) 14.58
2015.09 101.7 102.7 78.1 (66.3 projected, +0.0) 15.78
2015.10 104.1 103.3 61.7 (65.9 projected, -0.4) 14.02
2015.11 109.3 106.9 63.2 (63.8 projected, -2.1) 12.09
2015.12 112.9 109.5 57.7 (62.1 projected, -1.7) 13.8
2016.01 (98.9)   6.5 (2A) / 50.5 (2B) / 63.4 (2C) (60.4 projected, -1.7) (9.9)

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).
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.