Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 12, 2016 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 (March 4, 2016)
Solar cycle Solar cycles 23-24 (March 1, 2016) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24 progress (March 1, 2016) Noon SDO sunspot count 1K / 4K (*)
  Solar cycles 1-24 (July 17, 2015) POES auroral activity level October 2009 - December 2012
  Comparison of cycles 21, 22, 23 and 24 (March 1, 2016) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12, 13, 14, 16 and 24 (March 1, 2016) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs. solar cycles (March 12, 2016)  

Recent activity

The geomagnetic field was quiet to minor storm on March 11. Solar wind speed at SOHO ranged between 292 and 583 km/s. A co-rotating interaction region associated with CH720 was the most likely source of the initial part of the disturbance that began early in the day. The development of solar wind speed and the absence of a CME signature in low level protons are indicative of a coronal hole source.

Solar flux at 20h UTC on 2.8 GHz was 94.2 (decreasing 16.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 102.9. The Potsdam WDC planetary A index was 17 (STAR Ap - based on the mean of three hour interval ap indices: 16.9). Three hour interval K indices: 22335333 (planetary), 12344432 (Boulder).

The background x-ray flux is at the class B1 level.

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 123) and 7 active regions using 1K resolution (SN: 83) SDO images on the visible solar disk.

Region 12513 [N10W42] was quiet and stable.
Region 12518 [N05W55] decayed quickly and quietly.
Region 12519 [N05E49] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S5166 [N03W77] decayed slowly and quietly.
S5170 [N12E32] reemerged with tiny spots.
S5171 [N19E32] was quiet and stable.
S5177 [N04E32] developed slowly and quietly.
New region S5179 [N14W12] emerged with tiny spots.
New region S5180 [S37W70] emerged early in the day with several tiny spots, then decayed leaving only 1 spot at the end of the day.

C2+ flares:

Magnitude Peak time (UT) Location AR Recorded by Comment
           

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

Coronal mass ejections (CMEs)

March 8-10: 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 extension (CH721) of the southern polar coronal hole will likely rotate into an Earth facing position on March 12.

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 March 12 due to effects from CH720. Quiet conditions are likely on March 13-14. Quiet to minor storm conditions are possible on March 15-16 due to effects from CH721.

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.
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
12511 2016.02.29
2016.03.02
2     N02W79 0010 AXX      

actual location: N03W62

SWPC switched ARs 12511/12510 on March 3

SWPC then moved the region to the location of AR S5166 on March 8

12510 2016.03.01
2016.03.02
      N07W68           SWPC switched ARs 12510/12511 on March 3

actual location: N06W73

12513 2016.03.02 1 4 1 N10W44 0040 HSX CAO images/AR_12513_20160311_2345.png images/AR_12513_20160310_2345.png location: N10W42
S5163 2016.03.06       N12W50            
S5166 2016.03.07   1   N03W77 0001   AXX this is AR 12511 to SWPC
12518 2016.03.08
2016.03.09
2 2   N04W54 0010 AXX AXX area: 0003
S5169 2016.03.08       S08E09            
S5170 2016.03.08   3 1 N12E32 0007   BXO    
S5171 2016.03.08   4 1 N19E32 0010   AXX  
S5172 2016.03.08       S30W33            
12519 2016.03.09 3 8 4 N06E48 0050 CAO CAO area: 0140
S5175 2016.03.10       S05E41          
S5176 2016.03.10       N27W08          
S5177 2016.03.10   6 3 N04E32 0025   DRO  
S5178 2016.03.10       S12W25          
S5179 2016.03.11   4 2 N14W12 0013   CRO    
S5180 2016.03.11   1 1 S37W70 0003   AXX    
Total spot count: 8 33 13  
Sunspot number: 48 123 83  (total spot count + 10 * number of spotted regions)
Weighted SN: 18 49 29  (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): 53 55 66 k * (sunspot number)
As of February 19, 2015: k = 1.1 for SWPC, k = 0.45 for MSN 2K, k = 0.80 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
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 68.2 (-3.8) 8.83
2015.08 105.4 108.0 64.6 66.3 (-1.9) 14.58
2015.09 101.7 102.7 78.1 (66.0 projected, -0.3) 15.78
2015.10 104.1 103.3 61.7 (65.3 projected, -0.7) 14.02
2015.11 109.3 106.9 63.2 (63.2 projected, -2.1) 12.09
2015.12 113.1 109.5 57.7 (61.5 projected, -1.7) 14.29
2016.01 103.4 100.1 56.6 (59.8 projected, -1.7) 9.4
2016.02 103.6 101.0 57.2 (57.4 projected, -2.4) 9.9
2016.03 (96.6)   21.4 (2A) / 60.4 (2B) / 68.7 (2C) (54.5 projected, -3.1) (10.1)

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.