Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 5, 2014 at 05:10 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 4. Solar wind speed at SOHO ranged between 309 and 416 km/s.

Solar flux at 20h UTC on 2.8 GHz was 158.0 (decreasing 35.5 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: 21022112 (planetary), 22032312 (Boulder).

The background x-ray flux is at the class C1 level.

At the time of counting spots (see image time) spots were observed in 21 active regions in 2K resolution (SN: 402) and 15 active regions in 1K resolution (SN: 258) SDO images on the visible solar disk.

Region 11987 [S02W75] was quiet and stable.
Region 11989 [N08W55] decayed significantly and was quiet.
Region 11990 [S12W27] was quiet and stable.
Region 11991 [S25W10] decayed slowly and still has a magnetic delta structure in the trailing spot section. Further M class flaring is possible.
C5+ flare: C8.3/1F at 04:55 UTC. An M1.0 flare was recorded at 02:10 UTC on March 5.
Region 11993 [N17W22] developed slowly and quietly.
Region 11994 [S07W75] decayed slowly.
C5+ flare: long duration C5.6 event peaking at 07:04 UTC.
Region 11995 [S17W34] decayed significantly and was quiet.
Region 11996 [N13E30] gained spots and was quiet. There's polarity intermixing and a magnetic delta structure could easily form if the region develops further.
New region 11997 [S12W77] emerged with several spots.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3156 [N07W49] was quiet and stable.
S3163 [S10W53] was quiet and stable.
S3169 [N12W37] was quiet and stable.
S3181 [S16W06] reemerged with a penumbra spot.
S3182 [S12E03] was quiet and stable.
S3185 [N14E02] was quiet and stable.
S3186 [N10E13] was quiet and stable.
New region S3188 [S17E36] emerged with several penumbra spots.
New region S3189 [S10E80] rotated into view.
New region S3190 [S06E38] emerged with a penumbra spot.
New region S3191 [S24E22] emerged with a penumbra spot.
New region S3192 [S22W38] emerged with a few spots.

AR 11986 behind the northwest limb was quite active during the day and produced a number of C flares including C7.6 at 11:24 and a long duration C5.5 event peaking at 18:35 UTC.

Coronal mass ejections (CMEs)

March 2-4: 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) could rotate into an Earth facing position on March 5-6.

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 to fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be mostly quiet on March 5-8. Effects from CH606 could reach Earth on March 9 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 1 1 S01W76 0040 HSX HSX

area: 0130

location: S02W75

11989 2014.02.22
2014.02.23
8 16 7 N07W56 0070 CSO CRI

area: 0040

11994 2014.02.23
2014.02.28
2 1 1 S06W75 0090 HSX HSX area: 0050
S3156 2014.02.23   3 1 N07W49 0010   AXX  
11990 2014.02.24 6 14 7 S12W28 0190 CSO DHO

area: 0290

11991 2014.02.25
2014.02.26
25 48 35 S24W13 0240 EAC EAC beta-gamma-delta

area: 0440

location: S25W10

11992 2014.02.25
2014.02.26
      S19W63         plage
S3163 2014.02.25   2   S10W53 0006   AXX  
S3164 2014.02.25       N20W30         plage
11993 2014.02.25
2014.02.26
3 26 12 N16W23 0050 CSO DRI  
S3169 2014.02.26   3   N12W37 0008   BXO  
11995 2014.02.28 9 16 11 S17W34 0010 BXO CRI

area: 0040

S3173 2014.02.28       N15W06           plage
11996 2014.03.01
2014.03.02
14 35 20 N13E29 0060 CSI DRI area: 0180
S3176 2014.03.02       N09E45         plage
S3177 2014.03.02       N21W03           plage
S3180 2014.03.02       S06W23           plage
S3181 2014.03.02   1   S16W06          
S3182 2014.03.02   2 2 S12E03 0007   BXO  
S3185 2014.03.03   2   N14E02 0006   AXX  
S3186 2014.03.03   1   N10E13 0003   AXX  
11997 2014.03.04 2 8 4 S13W75 0010 BXO CRO   area: 0030
S3188 2014.03.04   6 2 S17E36 0003   BXO    
S3189 2014.03.04   2 2 S10E80 0170   HAX    
S3190 2014.03.04   1 1 S06E38 0004   AXX    
S3191 2014.03.04   1   S24E22 0002   AXX    
S3192 2014.03.04   3 2 S22W38 0012   HRX    
Total spot count: 70 192 108  
Sunspot number: 160 402 258  (total spot count + 10 * number of spotted regions)
Weighted SN: 105 240 156  (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): 96 141 142 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
2014.03 161.2 (1)   22.5 (2A) / 174.5 (2B) / 126.0 (2C) (71.0 projected, +0.1) (4.8)

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.