Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 7, 2015 at 05:50 UT.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update March 1, 2015)] [Cycle 24 progress (last update March 1, 2015) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update March 1, 2015)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update March 1, 2015)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update March 1, 2015)]

[Noon SDO sunspot count 1K Reference: 4K (large file) (updated daily)]

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated February 21, 2015]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to unsettled on March 6. Solar wind speed at SOHO ranged between 391 and 519 km/s, gradually increasing all day under the influence of a high speed stream from CH657.

Solar flux at 20h UTC on 2.8 GHz was 127.4 (decreasing 25.6 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 138.0. The Potsdam WDC planetary A index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 9.3). Three hour interval K indices: 13322123 (planetary), 12433323 (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 8 active regions using 2K resolution (SN: 135) and 6 active regions using 1K resolution (SN: 86) SDO images on the visible solar disk.

Region 12293 [N06W68] decayed slowly and quietly.
Region 12295 [S05W64] decayed slowly and quietly.
New region 12296 [S11E26] rotated into view on March 2 and was numbered by SWPC 4 days later as the region developed slowly.
New region 12297 [S17E80] rotated into view with a complex magnetic layout. Further M class flares are possible.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4251 [S03W37] decayed slowly and quietly.
S4256 [S12W15] was quiet and stable.
S4263 [S21W57] was quiet and stable.
New region S4270 [S23E34] was observed with penumbra spots.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
M3.0 (LDE) 04:57   12297 partial halo CME
M1.5 (LDE) 06:55   12297  
C2.5 15:08   12297  
C2.6 15:51   12297  
C2.2 21:11   12297  

Coronal mass ejections (CMEs)

March 4-5: No obviously Earth directed CMEs were observed in LASCO imagery.
March 6: A partial halo CME was observed after the M3 event in AR 12297

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 recurrent trans equatorial coronal hole (CH657) was in an Earth facing position on March 3-5. Another recurrent coronal hole (CH658) will likely rotate across the central meridian on March 9.

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 with occasional active intervals on March 7-9 due to effects from CH657.

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: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% 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
12293 2015.02.23
2015.02.26
4 7 5 N05W68 0010 AXX BXO images/AR_12293_20150306_2345.png images/AR_12293_20150305_2345.png  
S4246 2015.02.27       N17W57            
S4248 2015.02.28       S37W47            
S4251 2015.03.01   3   S03W37 0004   AXX  
12296 2015.03.02
2015.03.06
2 10 4 S11E24 0010 BXO HRX area: 0025
S4255 2015.03.02       N17W12            
S4256 2015.03.02   13 6 S12W15 0035   BXO images/AR_S4256_20150306_2345.png images/AR_S4256_20150305_2345.png  
S4258 2015.03.03       S14W31            
S4262 2015.03.04       N10E06            
S4263 2015.03.04   2 1 S21W57 0008   AXX  
12295 2015.03.04
2015.03.05
  1   S08W67 0001   AXX  
S4265 2015.03.05       S27E21         images/AR_S4265_20150305_2345.png  
S4266 2015.03.05       S44E20          
S4267 2015.03.05       S17W22          
12297 2015.03.06 1 15 8 S17E81 0030 HRX DAC   area: 0380
S4270 2015.03.06   3 2 S23E34 0007   BXO    
Total spot count: 7 54 26  
Sunspot number: 37 134 86  (total spot count + 10 * number of spotted regions)
Weighted SN: 10 62 34  (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): 22 47 47 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
2013.10  132.1 131.2 85.6 75.0 (+1.9) 7.71
2013.11  148.3 145.1 77.6 75.4 (+0.4) 5.68
2013.12 147.7 143.1 90.3 76.0 (+0.6) 4.68
2014.01 157.4 152.4 81.8 77.3 (+1.3) 5.44
2014.02 170.3
(cycle peak)
166.3 102.3 (cycle peak) 78.4 (+1.1) 10.70
2014.03 149.9 148.5 91.9 80.8 (+2.4) 4.88
2014.04 143.9 144.8 84.7 81.9 (+1.1)
(likely solar max)
7.88
2014.05 129.7 132.9 75.2 80.5 (-1.4) 5.75
2014.06 122.0 125.8 71.0 79.7 (-0.8) 6.72
2014.07 137.4 141.8 72.5 78.6 (-1.1) 4.50
2014.08 124.7 127.9 74.7 75.6 (-3.0) 7.71
2014.09 146.6 148.1 87.6 (71.6 projected, -4.0) 9.78
2014.10 153.4 152.9 60.6 (69.2 projected, -2.4) 8.96
2014.11 154.8 151.4 70.1 (67.4 projected, -1.8) 9.33
2014.12 158.7 153.8 78.0 (66.3 projected, -1.1) 11.24
2015.01 141.9 137.3 67.0 (65.1 projected, -1.2) 9.46
2015.02 129.1 126.0 44.8 (63.6 projected, -1.5) 9.92
2015.03 (126.9)   9.0 (2A) / 46.7 (2B) / 60.2 (2C) (61.6 projected, -2.0) (14.2)

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.