Solar Terrestrial Activity Report

Activity chart

Last major update issued on February 15, 2014 at 06:25 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 very quiet on February 14. Solar wind speed at SOHO ranged between 296 and 350 km/s.

Solar flux at 20h UTC on 2.8 GHz was 166.6 (increasing 37.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 149.6. The Potsdam WDC planetary A index was 2 (STAR Ap - based on the mean of three hour interval ap indices: 2.3). Three hour interval K indices: 00011000 (planetary), 00112321 (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 11 active regions in 2K resolution (SN: 283) and 7 active regions in 1K resolution (SN: 158) SDO images on the visible solar disk.

Region 11973 [N05W59] decayed further and was quiet.
Region 11974 [S11W45] was quiet and stable. SWPC is counting AR S3098 and this group as one.
Region 11976 [S15W03] was quiet and stable.
Region 11977 [S10E23] decayed slowly and quietly.
Region 11978 [N05W81] decayed slowly and quietly.
New region 11980 [S13E08] was finally split off from AR 11976 by SWPC
.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3098 [S11W37] decayed losing penumbral area and spots as well as getting a simpler magnetic layout. There is only a small magnetic delta structure left. A major flare is still a possibility, however, less flaring in general is expected compared to the level we have seen. C5+ flares: M2.3/2F at 02:57, C6.6 at 04:30, C7.2 at 10:41, M1.6/1N at 12:40, M1.1 at 13:28, M1.0 at 16:39, C6.6 at 17:24 UTC.
New region S3123 [S25W27] emerged early in the day, then decayed and had only one penumbra spot left by the end of the day.
New region S3124 [S23E78] rotated into view.
New region S3125 [N04W44] emerged with a penumbra spot.
New region S3126 [S25E38] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

February 13-14: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
February 12: A slow symmetric full halo CME was observed after an M2 flare in AR S3098. The CME could reach Earth on February 15.

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

No obvious coronal holes are currently in or near Earth facing positions.

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 quiet to active with a chance of minor storm intervals on February 15-16 due to CME effects. Quiet to unsettled is likely on February 17.

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
11971 2014.02.03
2014.02.04
1     S12W85 0030 HSX    

spotless

11973 2014.02.04
2014.02.05
1 1 1 N06W57 0020 HAX HRX

location: N05W59

area: 0012

11974 2014.02.04
2014.02.05
89 6 3 S12W37 0990 FKC CAO location: S11W45

area: 0090

S3096 2014.02.05       N15W53           plage
S3098 2014.02.06   88 42 S11W38 1030   EKC beta-gamma-delta

SWPC has this as part of AR 11974

11976 2014.02.07
2014.02.08
5 22 11 S15W03 0210 DSO DHO area: 0390
S3102 2014.02.08       S19W48           plage
11980 2014.02.09
2014.02.14
4 4 3 S14E06 0115 DAO CSO location: S13E08

area: 0200

11977 2014.02.10 21 47 27 S10E26 0410 EKC DKC area: 0560

location: S10E23

11978 2014.02.10
2014.02.11
5 1   N06W79 0010 BXO AXX location: N05W81

area: 0002

S3111 2014.02.11       N17W43           plage
S3112 2014.02.11       S32E09           plage
S3113 2014.02.11       N17W36           plage
S3114 2014.02.11       N30W49           plage
11979 2014.02.11
2014.02.12
      N13W68           plage
S3118 2014.02.12       N07W75         plage
S3120 2014.02.12       S25W30           plage
S3123 2014.02.14   1   S25W37 0003   AXX    
S3124 2014.02.14   1 1 S23E78 0005   AXX    
S3125 2014.02.14   1   N04W44 0003   AXX    
S3126 2014.02.14   1   S25E38 0003   AXX    
Total spot count: 126 173 88  
Sunspot number: 196 283 158  (total spot count + 10 * number of spotted regions)
Weighted SN: 166 216 131  (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): 118 99 87 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 (69.0 projected, +3.5) 8.27
2013.09 102.6 103.7 36.9 (73.0 projected, +4.0) 5.23
2013.10  132.1 131.2 85.6 (74.0 projected, +1.0) 7.71
2013.11  148.3 145.1 77.6 (72.9 projected, -1.1) 5.68
2013.12 147.7 143.1 90.3 (71.8 projected, -1.1) 4.68
2014.01 157.4
(cycle peak)
152.4 82.0 (71.0 projected, -0.8) 5.44
2014.02 177.4 (1)   83.6 (2A) / 180.2 (2B) / 107.9 (2C) (71.2 projected, +0.2) (7.4)

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.