Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 9, 2014 at 05:55 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update February 1, 2014)] [Cycle 24 progress (last update February 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update February 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update February 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update February 1, 2014)]

[POES auroral activity level since October 2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated February 1, 2014]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet to minor storm on February 8. Solar wind speed at SOHO ranged between 360 and 507 km/s.

Solar flux at 20h UTC on 2.8 GHz was 171.8 (increasing 16.5 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 150.0. The Potsdam WDC planetary A index was 22 (STAR Ap - based on the mean of three hour interval ap indices: 22.0). Three hour interval K indices: 54422244 (planetary), 44332324 (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 14 active regions in 2K resolution (SN: 329) and 12 active regions in 1K resolution (SN: 230) SDO images on the visible solar disk.

Region 11967 [S12W74] decayed slowly and produced only C flares despite the magnetic delta structure within the large trailing penumbra. C5+ flare: C8.6 at 18:33 UTC.
Region 11968 [N11W72] decayed slowly and was mostly quiet.
Region 11970 [S19W22] decayed slowly and quietly.
Region 11971 [S13W00] decayed slowly and quietly.
Region 11972 [S17W50] decayed quietly.
Region 11973 [N05E23] was quiet and stable.
Region 11974 [S11E34] gained spots and was quiet.
New region 11975 [S14W35] was first observed with spots on February 2, then decayed before emerging flux caused fairly quick development in the region from February 7. C flares are possible.
New region 11976 [S14E76] rotated partly into view on February and was numbered by SWPC the next day. C and minor M class flares are possible.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3082 [N07W11] reemerged with a penumbra spot.
S3090 [N18W18] was quiet and stable.
S3098 [S13E40] has weak polarity intermixing and could produce C flares.
S3099 [S28W03] was quiet and stable.
New region S3102 [S19E24] emerged with penumbra spots.

Coronal mass ejections (CMEs)

February 6-8: 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 recurrent trans equatorial coronal hole (CH602) was in an Earth facing position on February 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. Propagation on long distance northeast-southwest paths is fair.

Forecast

The geomagnetic field is expected to be quiet to active February 9-10 due to CME and coronal hole effects and quiet on February 11.

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
11967 2014.01.26
2014.01.27
19 13 10 S13W77 0830 FKC FKC beta-gamma-delta

area: 0780

location: S12W74

 

11968 2014.01.27 34 24 13 N11W72 0450 EKC EKC beta-gamma

area: 0380

S3075 2014.01.29       S12W48           plage
11970 2014.02.01
2014.02.02
  2   S17W30 0003   AXX

location: S19W22

S3082 2014.02.01   1 1 N07W11 0003   AXX    
11975 2014.02.02
2014.02.09
6 32 16 S15W37 0040 CSO DRI location: S14W35

area: 0130

11972 2014.02.02
2014.02.05
  1   S12W53 0002   AXX

location:S17W50

11971 2014.02.03
2014.02.04
12 27 18 S12W00 0070 DAO DRI

 

S3090 2014.02.03   1 1 N18W18 0004   AXX  
S3092 2014.02.04       S08W00         plage
11973 2014.02.04
2014.02.05
9 24 15 N05E24 0100 DSO DSI

area: 0160

11974 2014.02.04
2014.02.05
33 20 10 S13E37 0200 ESI CSI location: S11E34

area: 0180

see AR S3098

S3096 2014.02.05       N15E27           plage
S3098 2014.02.06   25 18 S13E40 0070   CAI beta-gamma

split off from AR 11974

S3099 2014.02.07   3 1 S28W03 0011   AXX  
11976 2014.02.07
2014.02.08
3 11 6 S15E78 0080 DAO DKO area: 0500

location: S14E76

S3101 2014.02.07       S23W38         plage
S3102 2014.02.08   5 1 S19E24 0011   BXO    
Total spot count: 116 189 110  
Sunspot number: 186 329 230  (total spot count + 10 * number of spotted regions)
Weighted SN: 161 240 161  (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): 112 115 127 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
2011.11 153.5   96.7 (cycle peak) 61.1 (+1.2) 5.55
2012.02 106.5   32.9 66.9 (+1.4) 8.81
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 (67.8 projected, +2.3) 8.27
2013.09 102.6 103.7 36.9 (69.6 projected, +1.8) 5.23
2013.10  132.1 131.2 85.6 (69.3 projected, -0.3) 7.71
2013.11  148.3 145.1 77.6 (67.5 projected, -1.8) 5.68
2013.12 147.7 143.1 90.3 (66.7 projected, -0.8) 4.68
2014.01 157.4
(cycle peak)
152.4 82.0 (66.9 projected, +0.2) 5.44
2014.02 184.7 (1)   55.2 (2A) / 193.1 (2B) / 104.8 (2C) (65.9 projected, -1.0) (7.1)

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 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.