Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 5, 2015 at 03:15 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 4. Solar wind speed at SOHO ranged between 432 and 510 km/s.

Solar flux at 20h UTC on 2.8 GHz was 124.2 (decreasing 17.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 138.1. The Potsdam WDC planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.1). Three hour interval K indices: 21133012 (planetary), 21243222 (Boulder).

The background x-ray flux is at the class B5 level.

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 166) and 8 active regions using 1K resolution (SN: 111) SDO images on the visible solar disk.

Region 12292 [S08W73] decayed quickly and was mostly quiet.
Region 12293 [N06W41] decayed slowly and quietly.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4251 [S04W07] was quiet and stable.
S4254 [S11E53] was quiet and stable.
S4256 [S09E12] was quiet and stable.
New region S4261 [N16W36] emerged with penumbra spots early in the day.
New region S4262 [N10E32] emerged with penumbra spots.
New region S4263 [S22W22] was observed with penumbra spots.
New region S4264 [S06W39] emerged with a penumbra spot.

C2+ flares (GOES):

Magnitude Peak time (UTC) Location AR Comment
C2.8 (LDE) 10:39 S11W67 12292  

Coronal mass ejections (CMEs)

March 2-4: No obviously Earth directed CMEs were observed in LASCO 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 recurrent trans equatorial coronal hole (CH657) will be in an Earth facing position on March 3-5.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle latitudes is poor and slowly improving. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet to unsettled on March 5 becoming quiet to active on March 6-7 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
12292 2015.02.22
2015.02.23
13 19 9 S08W70 0180 CAI DRI

area: 0070

location: S08W73

12293 2015.02.23
2015.02.26
10 29 12 N05W38 0070 CAO DAO images/AR_12293_20150304_2345.png images/AR_12293_20150303_2345.png location: N06W41
12294 2015.02.26
2015.02.27
      S14W83            
S4246 2015.02.27       N17W31            
S4248 2015.02.28       S37W21            
S4249 2015.02.28       S10W51          
S4251 2015.03.01   6 3 S04W07 0011   BXO  
S4253 2015.03.01       N22W47            
S4254 2015.03.02   5 1 S11E53 0012   AXX  
S4255 2015.03.02       N17E14            
S4256 2015.03.02   10 3 S09E12 0020   BXO images/AR_S4256_20150304_2345.png  
S4258 2015.03.03       S14W05          
S4261 2015.03.04   2 1 N16W35 0010   AXX    
S4262 2015.03.04   2   N10E32 0006   AXX    
S4263 2015.03.04   2 1 S22W22 0006   BXO    
S4264 2015.03.04   1 1 S06W39 0005   AXX    
Total spot count: 23 76 31  
Sunspot number: 43 166 111  (total spot count + 10 * number of spotted regions)
Weighted SN: 33 84 39  (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): 26 58 61 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 (126.8)   6.8 (2A) / 53.0 (2B) / 62.4 (2C) (61.6 projected, -2.0) (17.8)

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.