Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 3, 2015 at 06:05 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 minor storm on March 2. Solar wind speed at SOHO ranged between 437 and 562860 km/s under the influence of effects from a co-rotating interaction region.

Solar flux at 20h UTC on 2.8 GHz was 130.4 (decreasing 18.9 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 138.7. The Potsdam WDC planetary A index was 26 (STAR Ap - based on the mean of three hour interval ap indices: 26.5). Three hour interval K indices: 44553322 (planetary), 44644432 (Boulder).

The background x-ray flux is at the class B9 level.

At the time of counting spots (see image time), spots were observed in 8 active regions using 2K resolution (SN: 177) and 6 active regions using 1K resolution (SN: 114) SDO images on the visible solar disk.

Region 12292 [S09W43] developed significantly as new flux emerged centrally and a magnetic delta formed. An M class flare is possible.
Region 12293 [N06W11] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4249 [S12W20] was quiet and stable.
S4251 [S05E19] was quiet and stable.
S4252 [S21E08] was quiet and stable.
New region S4254 [S11E79] rotated into view with penumbra spots.
New region S4255 [N17E40] was observed with penumbra spots.
New region S4256 [S15E36] was observed with penumbra spots.

AR 12290 rotated behind the northwest limb and was very active during the day producing many C and M class flares. A major M8.2 flare was recorded at 01:35 UT on March 3. An X class flare is possible today while the region is still close to the northwest limb.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C2.3 03:01   12290  
C2.5 05:18   12290  
C2.9 05:55   12290  
M1.0/1F 06:39 N19W84 12290  
C3.2 07:10   12290  
C5.2 07:48   12290  
C3.2 08:41   12290  
C3.1 09:16 N20W85 12290  
M1.1 09:48   12290  
C5.5 10:34   12290  
C3.4 13:07   12290  
C2.1 14:13   12290  
M3.7 15:28   12290  
C3.9 17:37   12290  
M4.1 19:31   12290  
C6.0 23:16   12290  

Coronal mass ejections (CMEs)

February 28 - March 2: No obviously Earth directed CMEs were observed in LASCO imagery. Several halo CMEs were observed on February 28 and March 1, probably from backsided sources.

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]

An extension of the southern polar coronal hole rotated across the central meridian on February 26-28 and is the likely source of a co-rotating interaction region. A recurrent trans equatorial coronal hole (CH657) will likely rotate into an Earth facing position on March 3-4.

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 3-5.

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
12290 2015.02.18 1     N22W94 0030 HSX     rotated out of view

location: N20W93

12292 2015.02.22
2015.02.23
8 31 18 S08W44 0070 DAI DAC

beta-gamma-delta

area: 0260

12293 2015.02.23
2015.02.26
15 45 27 N06W12 0060 DAI DAI images/AR_12293_20150302_2345.png images/AR_12293_20150301_2345.png  
12294 2015.02.26
2015.02.27
1     S14W56 0010 AXX     spotless
S4246 2015.02.27       N17W05            
S4248 2015.02.28       S37E05            
S4249 2015.02.28   2 2 S12W20 0008   AXX  
S4251 2015.03.01   5 3 S05E19 0012   AXX  
S4252 2015.03.01   3   S21E08 0006   BXO  
S4253 2015.03.01       N22W21          
S4254 2015.03.02   4 2 S11E79 0010   BXO    
S4255 2015.03.02   3   N17E40 0008   AXX    
S4256 2015.03.02   4 2 S15E36 0010   AXX    
Total spot count: 25 97 54  
Sunspot number: 65 177 114  (total spot count + 10 * number of spotted regions)
Weighted SN: 40 107 64  (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): 39 62 63 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) 9.1
2015.03 (129.0)   4.2 (2A) / 65.5 (2B) / 64.1 (2C) (61.6 projected, -2.0) (27.2)

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.