Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 12, 2014 at 03:40 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 very quiet on March 11. Solar wind speed at SOHO ranged between 288 and 323 km/s.

Solar flux at 20h UTC on 2.8 GHz was 164.6 (increasing 4.5 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 154.0. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.8). Three hour interval K indices: 11111111 (planetary), 00112311 (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 9 active regions in 2K resolution (SN: 258) and 9 active regions in 1K resolution (SN: 189) SDO images on the visible solar disk.

Region 11996 [N14W66] still has a magnetic delta structure in a central penumbra and could produce further M class flaring. C5+ flares: M3.5/1F at 03:44, C6.7 at 18:43, C6.9 at 21:56 UTC.
Region 11998 [S10W11] lost penumbral area on the leader spots. There are many penumbra spots visible on both polarities.
Region 11999 [S16W58] reemerged with a penumbra spot.
Region 12000 [S10W25] was quiet and stable.
Region 12002 [S19E23] gained penumbral area but is a little less complex magnetically than one day ago with only one minor magnetic detla structure present. M class flares are possible.
C5+ flares: C9.7/1F at 16:27, C8.0 at 19:47 UTC.
Region 12003 [N06W23] developed slowly and quietly.
Region 12004 [S09E50] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
New region S3209 [N12E85] rotated partly into view with a large spot.
New region S3210 [S18W61] emerged to the southwest of AR 11999 with several penumbra spots.

AR 11991 at the southwest limb produced a C6.7 flare at 10:17 and an M1.4 flare at 12:07 UTC.

Coronal mass ejections (CMEs)

March 9-11: 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 fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on March 12-14 with a chance of a few unsettled intervals on March 12-13 due to possible effects from CH607.

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
17 25 14 N14W64 0190 EAC EAC

beta-gamma-delta

area: 0360

S3176 2014.03.02       N09W47           plage
11999 2014.03.04
2014.03.05
  1 1 S16W57 0004   AXX    
11998 2014.03.04
2014.03.05
4 37 17 S09W13 0060 CAO CAO location: S09E03

area: 0090

S3190 2014.03.04       S06W40           plage
S3191 2014.03.04       S24W56           plage
12000 2014.03.05
2014.03.06
  6 3 S11W28 0014   BXO location: S10W25
S3194 2014.03.05       N16W38           plage
S3196 2014.03.07       N10W34           plage
S3197 2014.03.07       N09W47           plage
S3199 2014.03.07       S27W34           plage
12002 2014.03.07
2014.03.08
27 51 32 S19E26 0210 EAC EKC beta-gamma-delta

area: 0720

location: S19E23

S3202 2014.03.08       N25W33           plage
S3204 2014.03.08       S01E04           plage
12004 2014.03.09
2014.03.10
1 12 6 S08E51 0010 AXX CRO area: 0030

location: S09E50

12003 2014.03.09
2014.03.10
9 29 21 N06W25 0070 DAO DAI area: 0120

location: N06W23

S3207 2014.03.09       N08W29           plage
S3208 2014.03.10       N05E49         plage
S3209 2014.03.11   1 1 N12E85 0380   HHX    
S3210 2014.03.11   6 4 S16W58 0020   BXO    
Total spot count: 58 168 99  
Sunspot number: 108 258 189  (total spot count + 10 * number of spotted regions)
Weighted SN: 78 206 137  (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): 65 90 104 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
2014.03 154.1 (1)   54.8 (2A) / 154.5 (2B) / 119.9 (2C) (71.0 projected, +0.1) (3.9)

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). 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.