Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 6, 2014 at 05:30 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 on March 5. Solar wind speed at SOHO ranged between 362 and 442 km/s, weakly under the influence of a low speed coronal hole stream.

Solar flux at 20h UTC on 2.8 GHz was 149.1 (decreasing 42.2 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 154.8. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 5.5). Three hour interval K indices: 11112212 (planetary), 11223321 (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 16 active regions in 2K resolution (SN: 307) and 15 active regions in 1K resolution (SN: 241) SDO images on the visible solar disk.

Region 11989 [N08W70] decayed further and was quiet.
Region 11990 [S12W40] was quiet and stable.
Region 11991 [S26W21] decayed significantly and was quieta after the M class event.
C5+ flare: M1.0 at 02:10 UTC.
Region 11993 [N17W33] decayed slowly and quietly.
Region 11995 [S17W46] decayed further and was quiet.
Region 11996 [N14E17] decayed slowly and quietly.
Region 11997 [S13W85] rotated partly out of view.
New region 11998 [S10E67] rotated into view on March 4 and was numbered by SWPC the next day.
New region 11999 [S17E22] emerged on March 4 and received its NOAA number the following day.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3169 [N10W50] was quiet and stable.
S3181 [S15W22] was quiet and stable.
S3182 [S11W10] was quiet and stable.
S3192 [S24W53] decayed slowly and quietly.
New region S3193 [S11E56] emerged with a few spots.
New region S3194 [N17E45] emerged with penumbra spots.
New region S3195 [N19W23] emerged with a few spots.

Coronal mass ejections (CMEs)

March 3-5: 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 northern hemisphere coronal hole (CH606) may have been in an Earth facing position on March 5-6, the coronal hole may be too far to the north to become geoeffective.

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 fair.

Forecast

The geomagnetic field is expected to be mostly quiet on March 6-7. Effects from CH606 could reach Earth on March 8 and cause some unsettled intervals.

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
11987 2014.02.21 1     S02W87 0060 HSX     rotated out of view
11989 2014.02.22
2014.02.23
3 3 3 N08W70 0030 BXO BXO

area: 0015

11994 2014.02.23
2014.02.28
1     S06W87 0030 HSX     rotated out of view
11990 2014.02.24 4 20 11 S12W41 0190 DSO CSI

area: 0260

11991 2014.02.25
2014.02.26
24 34 21 S24W25 0240 EAC EAI beta-gamma

location: S26W21

11992 2014.02.25
2014.02.26
      S19W77           plage
S3164 2014.02.25       N20W43           plage
11993 2014.02.25
2014.02.26
10 18 12 N16W36 0050 BXO BXI  
S3169 2014.02.26   5 2 N10W40 0011   BXO  
11995 2014.02.28 5 6 2 S16W50 0020 BXO AXX

area: 0013

location: S17W46

S3173 2014.02.28       N15W19           plage
11996 2014.03.01
2014.03.02
20 25 14 N14E15 0120 CSO CRI area: 0070
S3176 2014.03.02       N09E32           plage
S3177 2014.03.02       N21W16           plage
S3180 2014.03.02       S06W36           plage
S3181 2014.03.02   1 1 S15W22 0008   AXX  
S3182 2014.03.02   3 2 S11W10 0009   BXO  
S3185 2014.03.03       N14W11         plage
S3186 2014.03.03       N10W00         plage
11997 2014.03.04 5 1   S13W89 0080 BXO AXX area: 0006
11999 2014.03.04
2014.03.05
6 10 9 S17E22 0040 DRO DRI area: 0060
11998 2014.03.04
2014.03.05
2 9 7 S10E65 0060 CHO CAO location: S10E67
S3190 2014.03.04       S06E25         plage
S3191 2014.03.04       S24E09         plage
S3192 2014.03.04   3 1 S24W53 0008   BXO  
S3193 2014.03.05   4 2 S11E56 0030   CRO    
S3194 2014.03.05   2 1 N17E45 0006   AXX    
S3195 2014.03.05   3 3 N19W23 0020   DRO    
Total spot count: 81 147 91  
Sunspot number: 191 307 241  (total spot count + 10 * number of spotted regions)
Weighted SN: 119 174 116  (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): 115 107 133 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) 10.8
2014.03 158.8 (1)   28.7 (2A) / 177.8 (2B) / 126.6 (2C) (71.0 projected, +0.1) (5.0)

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.