Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 2, 2014 at 07:30 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 unsettled on March 1. Solar wind speed at SOHO ranged between 351 and 402 km/s.

Solar flux at 20h UTC on 2.8 GHz was 164.6 (decreasing 25.2 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 153.9. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 5.9). Three hour interval K indices: 21221113 (planetary), 11222222 (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 15 active regions in 2K resolution (SN: 339) and 14 active regions in 1K resolution (SN: 240) SDO images on the visible solar disk.

Region 11982 [S09W85] decayed slowly. C5+ flare: M1.1 at 13:33 UTC. 
Region 11986 [N14W51] decayed slowly and quietly.
Region 11987 [S01W32] decayed significantly in the trailing and intermediate spot sections.
Region 11989 [N08W15] was quiet and stable.
Region 11990 [S12E13] decayed slowly and was mostly quiet as the magnetic delta structure weakened.
Region 11991 [S24E27] developed as new flux emerged centrally. C and minor M class flares are possible.
Region 11992 [S19W21] decayed slowly and quietly.
Region 11993 [N16E18] decayed slowly in the trailing and intermediate spot sections and has polarity intermixing.
Region 11994 [S07W32] lost some small spots while the leader spot increased its penumbral area.
Region 11995 [S17E06] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3156 [N07W09] gained spots and was quiet.
S3163 [S09W08] was quiet and stable.
S3168 [S10W67] decayed slowly and quietly.
S3169 [N11E03] decayed slowly and quietly.
New region S3175 [N12E70] emerged with a few spots.

Coronal mass ejections (CMEs)

February 27 - March 1: 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 to fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on March 2 and quiet on March 3-4.

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 STAR SDO SWPC STAR Current Previous
2K 1K
11982 2014.02.16
2014.02.17
3 2 1 S11W86 0050 CAO HRX

location: S09W85

11986 2014.02.19
2014.02.20
  3   N14W55 0006   AXX

 

11987 2014.02.21 16 23 12 S02W29 0160 ESI DSI

area: 0200

location: S01W32

11988 2014.02.21
2014.02.22
7     S10W64 0170 DAO       plage

location: S10W57

SWPC has adopted the spots of AR S3168

S3150 2014.02.22       S15W56           plage
11989 2014.02.22
2014.02.23
7 10 4 N07W13 0010 BXO CRO

location: N08W15

S3154 2014.02.23       S27W58           plage
11994 2014.02.23
2014.02.28
3 6 3 S07W31 0030 HAX CAO area: 0070
S3156 2014.02.23   12 7 N07W09 0040   AXX  
S3159 2014.02.24       S22W55           plage
11990 2014.02.24 9 16 9 S14E11 0210 DAC DKC beta-delta

area: 0420

location: S12E13

11991 2014.02.25
2014.02.26
10 28 18 S25E26 0290 EKO EKC beta-gamma

area: 0580

location: S24E27

11992 2014.02.25
2014.02.26
1 4 1 S19W19 0020 HSX CRO location: S19W21
S3163 2014.02.25   3 1 S09W08 0010   AXX  
S3164 2014.02.25       N21E06            
11993 2014.02.25
2014.02.26
13 35 15 N16E16 0110 DAI DAI beta-gamma

location: N16E18

 

S3166 2014.02.25       N06W41           plage
S3168 2014.02.26   8 5 S10W67 0180   EAO AR 11988 for SWPC
S3169 2014.02.26   4 1 N11E03 0012   BXO  
S3171 2014.02.27       N01W55           plage
11995 2014.02.28 8 29 19 S17E06 0060 CAO DRI

area: 0080

S3173 2014.02.28       N15E35         plage
S3174 2014.02.28       S08W25         plage
S3175 2014.03.01   6 4 N12E70 0035   CRO    
Total spot count: 77 189 100  
Sunspot number: 177 339 240  (total spot count + 10 * number of spotted regions)
Weighted SN: 127 244 155  (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): 106 119 132 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for STAR SDO 2K, k = 0.55 for STAR SDO 1K

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) 10.8
2014.03 164.2 (1)   5.7 (2A) / 177 (2B) / 120.6 (2C) (71.0 projected, +0.1) (5.9)

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.