Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 17, 2014 at 05:20 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 very quiet on March 16. Solar wind speed at SOHO ranged between 276 and 373 km/s.

Solar flux at 20h UTC on 2.8 GHz was 136 (decreasing 16.4 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 153.2. The Potsdam WDC planetary A index was 1 (STAR Ap - based on the mean of three hour interval ap indices: 1.4). Three hour interval K indices: 00100000 (planetary), 01202210 (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 13 active regions in 2K resolution (SN: 266) and 10 active regions in 1K resolution (SN: 174) SDO images on the visible solar disk.

Region 12002 [S18W42] developed in the trailing spot section as new flux emerged (could split off as a new region if the development continues) and decayed slowly elsewhere.
Region 12004 [S11W13] developed slowly and quietly.
Region 12005 [N12E21] developed slowly and quietly, there's minor polarity intermixing.
Region 12008 [S11E59] decayed slowly and quietly.
New region 12009 [N13W02] emerged on March 13, was spotless on March 14 and reemerged with spots on March 15 with SPWC waiting until March 16 to assign a region number.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3208 [N10W26] reemerged with a penumbra spot.
S3225 [S15E49] was quiet and stable.
S3226 [S09E48] developed slowly and quietly.
S3227 [S21E07] lost the trailing spots.
New region S3229 [S07E24] emerged early in the day.
New region S3230 [S15E77] rotated into view.
New region S3231 [S19E39] emerged with a penumbra spot.
New region S3232 [S24E35] emerged with penumbra spots.

AR 12003 produced a C7.3 flare at 06:45 UTC while at the northwest limb.
A filament eruption in the southeast quadrant was observed beginning at 02:12 UTC and may have been associated with a CME.

Coronal mass ejections (CMEs)

March 14-16: 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) could rotate into 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 to fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on March 17-19.

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
1     S07W79 0000 AXX    

spotless

12002 2014.03.07
2014.03.08
24 53 27 S18W44 0280 EKC EAC

location: S18W42

12004 2014.03.09
2014.03.10
4 26 17 S10W17 0010 BXO DRI images/AR_12004_20140316_2345.png images/AR_12004_20140315_2345.png

location: S11W13

12003 2014.03.09
2014.03.10
5     N05W91 0120 DAO     rotated out of view
S3208 2014.03.10   1   N09W21 0002   AXX   plage
12005 2014.03.11
2014.03.12
3 24 16 N13E19 0250 CHO FKO area: 0430

location: N12E21

S3213 2014.03.12       N20W45           plage
12007 2014.03.13
2014.03.14
2     N11E37 0030 HAX       trailing spots of AR 12005
12009 2014.03.13
2014.03.16
4 8 5 N14W02 0010 BXO DRO  
S3216 2014.03.13       S01W17           plage
S3217 2014.03.13       S26W21           plage
12006 2014.03.13
2014.03.14
5     N11W89 0190 DSI     rotated out of view
12008 2014.03.14
2014.03.15
1 2 1 S11E59 0030 HAX HRX  
S3223 2014.03.14       S05W47           plage
S3225 2014.03.15   4 2 S15E49 0018   BXO reversed polarities
S3226 2014.03.15   6 3 S09E48 0018   CRO  
S3227 2014.03.15   3 1 S21E07 0007   AXX  
S3229 2014.03.16   4 1 S07E24 0015   CRO    
S3230 2014.03.16   2   S15E77 0004   BXO    
S3231 2014.03.16   1 1 S19E39 0004   AXX    
S3232 2014.03.16   2   S24E35 0005   AXX    
Total spot count: 49 136 74  
Sunspot number: 139 266 174  (total spot count + 10 * number of spotted regions)
Weighted SN: 89 166 104  (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): 83 93 96 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
2014.03 150.5 (1)   76.6 (2A) / 148.5 (2B) / 115.5 (2C) (71.0 projected, +0.1) (4.5)

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.