Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 13, 2014 at 04:30 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update March 1, 2014)] [Cycle 24 progress (last update March 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update March 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update March 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update March 1, 2014)]

[POES auroral activity level since October 2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated February 23, 2014]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet to unsettled on March 12. Solar wind speed at SOHO ranged between 275 and 317 km/s. A disturbance began slowly late in the day, possibly due to effects from CH607. Active conditions have been observed early on March 13.

Solar flux at 20h UTC on 2.8 GHz was 147.6 (decreasing 19.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 153.9. The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.0). Three hour interval K indices: 32221123 (planetary), 20111212 (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 11 active regions in 2K resolution (SN: 240) and 10 active regions in 1K resolution (SN: 171) SDO images on the visible solar disk.

Region 11996 [N14W80] was the most active region on the visible disk. There is a magnetic delta structure in the central section and further M class flares are possible on March 13-14 while the region is at or just behind the northwest limb. C5+ flares: C7.2 at 07:57, M2.5 at 11:05, C5.3 at 17:40, major M9.3 at 22:34 UTC.
Region 11998 [S09W25] decayed losing all umbra.
Region 12000 [S11W33] decayed and lost the leader spot.
Region 12002 [S19E10] decayed slowly and was mostly quiet. The region has a magnetic delta structure and could produce an M class flare.

Region 12003 [N06W37] developed further and was mostly quiet.
Region 12004 [S08E37] decayed slowly and quietly.
New region 12005 [N12E71] rotated into view on March 11 and was numbered the next day by SWPC.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3210 [S18W73] was quiet and stable.
New region S3211 [S09W48] emerged just ahead of AR 12000.
New region S3212 [N17W26] emerged with penumbra spots.
New region S3213 [N20E07] emerged with a penumbra spot.

An active region 4-5 days behind the northeast limb produced a large flare at 14:16 UTC, this event was associated with a halo CME.

Coronal mass ejections (CMEs)

March 10-12: No obviously Earth directed CMEs were observed in LASCO and STEREO 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 small southern hemisphere coronal hole (CH607) was in an Earth facing position on March 9.

Coronal hole map

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 active on March 13, likely due to effects from CH607. Quiet conditions are likely on March 14-15.

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: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% 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
11996 2014.03.01
2014.03.02
16 13 6 N14W78 0220 EAC EAC

beta-gamma-delta

area: 0330

location: N14W80

11999 2014.03.04
2014.03.05
3     S18W74 0010 BXO     spotless

real location: S14W70

SWPC has adopted the spots of AR S3210

11998 2014.03.04
2014.03.05
9 20 10 S09W26 0040 CAO CRO

 

S3190 2014.03.04       S06W53           plage
12000 2014.03.05
2014.03.06
  1   S11W42 0002   AXX location: S11W33
S3194 2014.03.05       N16W51           plage
S3196 2014.03.07       N10W47           plage
S3199 2014.03.07       S27W47           plage
12002 2014.03.07
2014.03.08
25 32 20 S18E09 0380 EKC ESC beta-gamma-delta

area: 0540

location: S19E10

S3202 2014.03.08       N25W46           plage
S3204 2014.03.08       S01W09           plage
12004 2014.03.09
2014.03.10
1 12 2 S09E36 0010 AXX BXO area: 0022

location: S08E37

12003 2014.03.09
2014.03.10
20 33 20 N06W39 0130 DAC DKC area: 0380

location: N06W37

S3207 2014.03.09       N08W42           plage
S3208 2014.03.10       N05E36           plage
12005 2014.03.11
2014.03.12
1 1 1 N12E68 0100 HSX HHX area: 0370

location: N12E71

S3210 2014.03.11   7 4 S18W73 0040   BXO  
S3211 2014.03.12   7 5 S09W48 0020   BXO    
S3212 2014.03.12   3 2 N17W26 0012   BXO    
S3213 2014.03.12   1 1 N20E07 0003   AXX    
Total spot count: 75 130 71  
Sunspot number: 145 240 171  (total spot count + 10 * number of spotted regions)
Weighted SN: 105 163 104  (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): 87 84 94 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
2012.11 121.3 118.3 61.8 59.7 (+1.1) 7.08
2012.12 108.6 105.0 40.8 59.6 (-0.1) 3.44
2013.01 127.1 123.1 62.9 58.7 (-0.9) 4.69
2013.02 104.3 101.8 38.0 58.4 (-0.3) 6.11
2013.03 111.3 110.2 57.9 57.5 (-0.9) 10.56
2013.04 124.8 125.9 72.4 57.9 (+0.4) 5.40
2013.05 131.4 134.3 78.7 59.9 (+2.0) 9.73
2013.06 110.1 113.7 52.5 62.6 (+2.7) 12.60
2013.07 115.5 119.3 57.0 65.5 (+2.9) 9.47
2013.08 114.6 118.3 66.0 69.0 (+3.5) 8.27
2013.09 102.6 103.7 36.9 (72.8 projected, +3.8) 5.23
2013.10  132.1 131.2 85.6 (73.8 projected, +1.0) 7.71
2013.11  148.3 145.1 77.6 (72.7 projected, -1.1) 5.68
2013.12 147.7 143.1 90.3 (71.6 projected, -1.1) 4.68
2014.01 157.4 152.4 82.0 (71.6 projected, 0.0) 5.44
2014.02 170.3
(cycle peak)
166.3 102.8 (cycle peak) (70.9 projected, -0.7) 10.70
2014.03 153.5 (1)   59.5 (2A) / 153.8 (2B) / 119.4 (2C) (71.0 projected, +0.1) (4.2)

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.