Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 22, 2014 at 07:20 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 March 16, 2014]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet to unsettled on March 21. Solar wind speed at SOHO ranged between 289 and 389 km/s. ACE data indicate that a weak stream from CH608 has arrived early on March 22.

Solar flux at 20h UTC on 2.8 GHz was 152.6 (decreasing 10.6 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 153.0. The Potsdam WDC planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.1). Three hour interval K indices: 22222312 (planetary), 32333412 (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 17 active regions in 2K resolution (SN: 357) and 17 active regions in 1K resolution (SN: 269) SDO images on the visible solar disk.

Region 12004 [S10W78] decayed further leaving only penumbra spots as the region rotate to the southwest limb.
Region 12005 [N11W47] decayed slowly and quietly.
Region 12008 [S11W09] was quiet and stable.
Region 12010 [S15E14] gained spots and developed a weak magnetic delta structure as positive polarity flux emerged in the trailing spot section. A minor M class flare is possible.
Region 12011 [S08W65] gained penumbral area. There is a weak magnetic delta structure in the southern part of the leader spot. An M class flare is possible.
Region 12012 [S12E24] reemerged with penumbra spots.
Region 12013 [N13E28] was quiet and stable.
Region 12014 [S13E47] regained umbra on the trailing polarity
.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3225 [S14W13] reemerged with several spots.
S3226 [S10W19] decayed slowly and produced a few low level C flares. SWPC has moved AR 12008 10 degrees to the west to include the spots in AR S3226.
S3236 [S28E20] developed slowly and quietly.
S3241 [N14W00] was quiet and stable.
S3248 [S01E58] decayed slightly and lost the umbra.
S3249 [S05W47] was quiet and stable.
New region S3251 [S09W38] emerged with a penumbra spot.
New region S3253 [N10E73] rotated into view.
New region S3254 [S02E06] emerged with penumbra spots.

Coronal mass ejections (CMEs)

March 19-21: 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 trans equatorial coronal hole (CH608) was in an Earth facing position on March 19-20.

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 on March 22-23 with a chance of unsettled intervals due to weak effects from CH608. Quiet conditions are likely on March 24.

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
12004 2014.03.09
2014.03.10
5 2 1 S09W85 0030 CAO AXX

location: S10W79

area: 0010

12005 2014.03.11
2014.03.12
1 7 1 N13W47 0200 HSX CHO images/AR_12005_20140321_2345.png images/AR_12005_20140320_2345.png area: 0270

location: N11W47

12007 2014.03.13
2014.03.14
      N11W33           trailing part of AR 12005
12009 2014.03.13
2014.03.16
      N14W72           plage

location: N11W71

12008 2014.03.14
2014.03.15
11 10 5 S10W19 0050 DAI BXO area: 0020

SWPC has moved the region 10 degrees to the west and currently counts the spots of AR S3226.

real location: S11W09

S3225 2014.03.15   15 6 S14W13     DRI    
S3226 2014.03.15   24 15 S10W19 0090   DRI  
S3227 2014.03.15       S26W27         plage
S3229 2014.03.16       S08W41           plage
12010 2014.03.16
2014.03.17
13 52 30 S15E13 0130 DAC DAC

beta-gamma-delta

area: 0340

S3231 2014.03.16       S19W26           plage
S3232 2014.03.16       S24W30           plage
S3233 2014.03.17       S27E04         plage
12012 2014.03.17
2014.03.18
  4 3 S09E19 0013   BXO   location: S12E24
12013 2014.03.17
2014.03.18
1 9 3 N13E30 0030 HAX CSO area: 0080
S3236 2014.03.17   10 7 S28E20 0035   CRO  
S3237 2014.03.17       S23W12           plage
12011 2014.03.18 12 21 8 S07W63 0220 DAO DKC beta-gamma-delta

area: 0460

location: S08W65

12014 2014.03.18
2014.03.19
12 19 11 S15E47 0150 DAO DAO

location: S13E47

area: 0240

S3241 2014.03.18   4 1 N14W00 0012   BXO  
S3242 2014.03.18       N21W31           plage
S3244 2014.03.19       N17E15           plage
S3245 2014.03.19       S18W22         plage
S3246 2014.03.19       S02W15           plage
S3248 2014.03.20   2 1 S01E58 0010   AXX  
S3249 2014.03.20   2 2 S05W47 0006   BXO  
S3250 2014.03.20       N39W04         plage
S3251 2014.03.21   1 1 S09W38 0008   AXX    
S3253 2014.03.21   3 2 N10E73 0030   CRO    
S3254 2014.03.21   2 2 S02E06 0010   AXX    
Total spot count: 55 187 99  
Sunspot number: 125 357 269  (total spot count + 10 * number of spotted regions)
Weighted SN: 85 234 146  (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): 75 125 148 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
2014.03 149.3 (1)   97.1 (2A) / 143.3 (2B) / 119.7 (2C) (71.0 projected, +0.1) (4.6)

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.