Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 4, 2014 at 03:45 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 3. Solar wind speed at SOHO ranged between 299 and 374 km/s.

Solar flux at 20h UTC on 2.8 GHz was 161.0 (decreasing 27.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 154.5. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.8). Three hour interval K indices: 22212011 (planetary), 22212222 (Boulder).

The background x-ray flux is at the class B8 level.

At the time of counting spots (see image time) spots were observed in 17 active regions in 2K resolution (SN: 362) and 14 active regions in 1K resolution (SN: 245) SDO images on the visible solar disk.

Region 11987 [S02W60] decayed slowly and quietly.
Region 11989 [N08W42] produced several low level C flares prior to the M class flare, after which the region began to decay.
C5+ flare: impulsive M1.2 at 15:58 UTC.
Region 11990 [S12W13] decayed slowly and quietly.
Region 11991 [S25E02] still has a magnetic delta structure in the trailing spot section, an M class flare is possible.
Region 11992 [S20W43] lost the leader spot while a trailing penumbra spot emerged.
Region 11993 [N17W09] decayed slowly and quietly.
Region 11994 [S07W61] decayed slowly and quietly.
Region 11995 [S17W20] was quiet and stable.
Region 11996 [N13E43] developed slowly and quietly.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3156 [N07W36] was quiet and stable.
S3163 [S14W32] was quiet and stable.
S3164 [N20W17] was quiet and stable.
S3169 [N12W23] reemerged with penumbra spots.
S3176 [N09E58] gained a few penumbra spots.
S3182 [S12E17] was quiet and stable.
New region S3185 [N14E16] emerged with a penumbra spot.
New reigon S3186 [N09E29] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

March 1-3: 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 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 4-8. 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 STAR SDO SWPC STAR Current Previous
2K 1K
11986 2014.02.19
2014.02.20
      N14W83          

plage

11987 2014.02.21 10 4 2 S02W56 0130 CSO CSO

area: 0120

location: S02W60

11988 2014.02.21
2014.02.22
1     S08W87 0010 AXX       plage

location: S10W83

SWPC has adopted the spots of AR S3168

11989 2014.02.22
2014.02.23
9 18 8 N08W42 0060 CAO DRI

area: 0100

11994 2014.02.23
2014.02.28
2 2 2 S07W61 0040 HSX HSX area: 0070
S3156 2014.02.23   7 5 N07W36 0020   AXX  
11990 2014.02.24 7 14 6 S12W17 0210 DAC DSC

area: 0290

location: S12W13

11991 2014.02.25
2014.02.26
33 50 31 S23W00 0330 EKI EAC beta-gamma-delta

area: 0540

location: S25E02

11992 2014.02.25
2014.02.26
1 1 1 S19W49 0010 AXX AXX area: 0003

location: S20W43

S3163 2014.02.25   5 3 S14W32 0012   AXX  
S3164 2014.02.25   2   N20W17 0005   BXO  
11993 2014.02.25
2014.02.26
8 17 7 N16W11 0030 CAO DRI  
S3169 2014.02.26   8 2 N12W23 0015   BXO    
11995 2014.02.28 13 29 18 S17W22 0050 CAO DRI

area: 0080

S3173 2014.02.28       N15E09           plage
S3174 2014.02.28       S08W51           plage
11996 2014.03.01
2014.03.02
7 25 16 N14E42 0060 CAI DRI area: 0120
S3176 2014.03.02   6 2 N09E58 0014   BXO  
S3177 2014.03.02       N21E10         plage
S3180 2014.03.02       S06W10         plage
S3181 2014.03.02       S13E04         plage
S3182 2014.03.02   2 2 S12E17 0007   BXO  
S3185 2014.03.03   1   N14E16 0002   AXX    
S3186 2014.03.03   1   N09E29 0002   AXX    
Total spot count: 91 192 105  
Sunspot number: 191 362 245  (total spot count + 10 * number of spotted regions)
Weighted SN: 141 224 137  (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): 115 127 135 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for STAR SDO 2K, k = 0.55 for STAR SDO 1K

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
2014.03 162.3 (1)   17.4 (2A) / 179.3 (2B) / 124.6 (2C) (71.0 projected, +0.1) (4.6)

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.