Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 15, 2014 at 07:15 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 on March 14. Solar wind speed at SOHO ranged between 361 and 488 km/s.

Solar flux at 20h UTC on 2.8 GHz was 143.8 (decreasing 18.3 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 153.5. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.6). Three hour interval K indices: 12211111 (planetary), 12223311 (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 9 active regions in 2K resolution (SN: 202) and 7 active regions in 1K resolution (SN: 128) SDO images on the visible solar disk.

Region 11998 [S09W52] decayed slowly and quietly.
Region 12002 [S19W17] simplified magnetically. The region still has many spots but has been quiet recently.

Region 12003 [N06W63] became more complex with negative polarity flux emerging in the trailing spot section.
Region 12004 [S12E08] was quiet and stable.
Region 12005 [N12E48] was quiet and stable.
New regio 12006 [N11W62] emerged on March 13 and was numbered by SWPC the next day.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3212 [N17W52] decayed slowly and quietly.
New region S3222 [S10E81] rotated into view.
New region S3223 [S05W21] emerged early in the day and appeared to be decaying late in the day.

Coronal mass ejections (CMEs)

March 12-14: 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

No obvious coronal holes are currently in or near Earth facing positions.

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.

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
11998 2014.03.04
2014.03.05
5 5 3 S09W52 0030 CRO CRO

 

12000 2014.03.05
2014.03.06
      S09W75           plage

real location: S11W63

SWPC has adopted the location of AR S3211

12002 2014.03.07
2014.03.08
33 54 28 S18W18 0330 EHC ESC

area: 0520

S3204 2014.03.08       S01W35           plage
12004 2014.03.09
2014.03.10
  16 9 S09E08 0050   BXO

location: S12E08

12003 2014.03.09
2014.03.10
12 15 9 N06W64 0180 DAO DAC area: 0380
S3208 2014.03.10       N09E05         plage
12005 2014.03.11
2014.03.12
1 4 2 N12E43 0180 HSX FHO area: 0400

location: N11E48

S3211 2014.03.12       S09W74         plage
S3212 2014.03.12   1   N17W52 0002   BXO  
S3213 2014.03.12       N20W19           plage
12007 2014.03.13
2014.03.14
1     N09E60 0030 HAX     merged with AR 12005

location: N10E64

S3215 2014.03.13       N11E26         plage
S3216 2014.03.13       S01E09         plage
S3217 2014.03.13       S26E05         plage
12006 2014.03.13
2014.03.14
9 14 6 N11W61 0040 CAO DAC area: 0140
S3222 2014.03.14   2 1 S10E81 0020   BXO    
S3223 2014.03.14   1   S05W21 0002   AXX    
Total spot count: 61 112 58  
Sunspot number: 121 202 128  (total spot count + 10 * number of spotted regions)
Weighted SN: 94 140 86  (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): 72 71 70 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
2014.03 152.4 (1)   67.6 (2A) / 149.7 (2B) / 115.6 (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.