Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 14, 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 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 active on March 13. Solar wind speed at SOHO ranged between 304 and 494 km/s under the influence of a stream from CH607.

Solar flux at 20h UTC on 2.8 GHz was 147.7 (decreasing 18.9 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 153.7. The Potsdam WDC planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 10.3). Three hour interval K indices: 43312121 (planetary), 43312211 (Boulder).

The background x-ray flux is at the class B8 level.

At the time of counting spots (see image time) spots were observed in 13 active regions in 2K resolution (SN: 272) and 13 active regions in 1K resolution (SN: 206) SDO images on the visible solar disk.

Region 11998 [S09W39] decayed slowly and quietly.
Region 12002 [S19W03] was mostly quiet and stable. The region has a magnetic delta structure and could produce an M class flare.

Region 12003 [N06W50] decayed slowly and quietly.
Region 12004 [S11E22] developed slowly and quietly.
Region 12005 [N12E58] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3211 [S09W61] decayed slowly and quietly.
S3212 [N17W38] was quiet and stable.
New region S3214 [N10E78] rotated into view. Although likely a region on its own, there is a chance the spots could be the trailing section of AR 12005. This will be easier to determine when the spots rotate into better view.
New region S3215 [N11E39] emerged with penumbra spots.
New region S3216 [S01E22] emerged with penumbra spots and the polarity layout of a northern hemisphere region.
New region S3217 [S26E18] emerged with a penumbra spot.
New region S3218 [N11W48] emerged quickly during the latter half of the day just north of AR 12003. C flares are possible, further development could cause larger flares.

AR 11996 behind the northwest limb produced the only noteworthy flare of the day, an M1.2 flare at 19:19 UTC.

Coronal mass ejections (CMEs)

March 11-13: 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 poor to fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on March 14 and quiet on March 15-16.

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
3     N16W90 0060 DAO     rotated out of view
11999 2014.03.04
2014.03.05
3     S17W86 0020 CAO       spotless

real location: S14W83

SWPC has adopted the spots of AR S3210

11998 2014.03.04
2014.03.05
6 20 9 S08W40 0020 CAO CRO

area: 0040

12000 2014.03.05
2014.03.06
5     S09W61 0020 CRO     spotless

real location: S11W50

SWPC has adopted the spots of AR S3211

12002 2014.03.07
2014.03.08
26 53 31 S19W05 0380 EKC EAC beta-gamma-delta

area: 0510

location: S19W03

S3202 2014.03.08       N25W59           plage
S3204 2014.03.08       S01W22           plage
12004 2014.03.09
2014.03.10
  23 9 S09E22 0050   BXO

location: S11E22

12003 2014.03.09
2014.03.10
16 20 10 N06W51 0180 DAC DKI area: 0310
S3207 2014.03.09       N08W55           plage
S3208 2014.03.10   1 1 N09E18 0005   AXX    
12005 2014.03.11
2014.03.12
1 1 1 N12E57 0170 HSX HHX area: 0330

location: N12E58

S3210 2014.03.11       S18W86         plage
S3211 2014.03.12   3 1 S09W61 0009   BXO  
S3212 2014.03.12   4 1 N17W38 0012   BXO  
S3213 2014.03.12       N20W06         plage
S3214 2014.03.13   2 2 N10E78 0050   HSX   possibly the trailing spots of AR 12005
S3215 2014.03.13   2 1 N11E39 0007   AXX    
S3216 2014.03.13   2 2 S01E22 0009   BXO    
S3217 2014.03.13   1 1 S26E18 0005   AXX    
S3218 2014.03.13   10 7 N11W48 0045   DRO    
Total spot count: 60 142 76  
Sunspot number: 130 272 206  (total spot count + 10 * number of spotted regions)
Weighted SN: 96 178 112  (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): 78 95 113 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
2014.03 153.1 (1)   63.7 (2A) / 151.9 (2B) / 118.1 (2C) (71.0 projected, +0.1) (4.7)

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.