Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 8, 2014 at 05:40 UTC.

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

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated June 4, 2014]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to active on June 7. Solar wind speed at SOHO ranged between 337 and 449 km/s. A solar wind shock was observed at SOHO at 15:56 UTC when the June 4 CME arrived.

Solar flux at 20h UTC on 2.8 GHz was 136.7 (decreasing 27.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 139.3. The Potsdam WDC planetary A index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 10.9). Three hour interval K indices: 21111344 (planetary), 22222434 (Boulder).

The background x-ray flux is at the class B5 level.

At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 276) and 10 active regions using 1K resolution (SN: 203) SDO images on the visible solar disk.

Region 12077 [S03W38] decayed slowly and quietly.
Region 12079 [N12W13] was quiet and stable.
Region 12080 [S11E04] displayed less activity than during the previous day and lost one of the magnetic delta structures in the trailing spot section. An M class flare is possible.
Region 12081 [N05W07] decayed slowly and quietly.
Region 12082 [N16E12] decayed in the trailing spot section with significant penumbral fragmentation.
Region 12084 [S12W27] decayed slowly and quietly.
Region 12085 [S20E09] developed further and has gained a magnetic delta structure in the trailing spot section. An M class flare is possible.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3499 [S09W03] was quiet and stable.

S3510 [S11E20] was quiet and stable.
New region S3512 [N16E70] rotated into view with a penumbra spot.
New region S3515 [S17E32] emerged with several spots.
New region S3516 [N22E63] emerged with a penumbra spot.

C2+ Flares (GOES):

Magnitude Time (UTC) Location AR
C3.0 06:25 SW limb 12083

Coronal mass ejections (CMEs)

June 5-7: 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

An extension (CH621) of a large southern hemisphere coronal hole may have been in an Earth facing position on June 6. A small trans equatorial coronal hole (CH622) could rotate into an Earth facing position on June 8.

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 to good.

Forecast

The geomagnetic field is expected to be quiet to minor storm on June 7 with a chance of major storm intervals due to CME effects. Mostly quiet conditions are likely on June 9-10.

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: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% 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
12077 2014.05.30 8 8 5 S04W38 0080 DSO DSO

area: 0120

12078 2014.05.30
2014.06.01
      S20W71           plage

real location: S19W66

12079 2014.05.31
2014.06.01
1 6 3 N12W13 0100 HSX HSX area: 0170
S3492 2014.05.31       N11W36         plage
12081 2014.06.01
2014.06.04
  1   N05W11 0010   BXO location: N05W07
S3495 2014.06.01       S10W53           plage
S3496 2014.06.02       N17W13           plage
12080 2014.06.02
2014.06.03
33 40 26 S12E04 0230 DAC DAC beta-gamma-delta

area: 0580

S3499 2014.06.03   4 2 S09W03 0010   AXX  
S3501 2014.06.04       S23E03           plage
S3502 2014.06.04       S12W14           plage
12082 2014.06.04
2014.06.05
13 28 21 N16E12 0320 DKI DKI area: 0420
12083 2014.06.04
2014.06.05
1     S12W91 0010 AXX     plage
S3505 2014.06.05       S15E33           plage
12085 2014.06.05
2014.06.06
24 46 34 S20E09 0180 DAI DAC beta-gamma-delta

area: 0400

12084 2014.06.06 5 7 5 S12W28 0030 DRO CRO  
S3507 2014.06.06       N12W24         plage
S3510 2014.06.06   4 2 S11E20 0010   AXX  
S3512 2014.06.07   1 1 N16E70 0004   AXX    
S3515 2014.06.07   10 4 S17E32 0020   DRO    
S3516 2014.06.07   1   N22E63 0003   AXX    
Total spot count: 85 156 103  
Sunspot number: 155 276 203  (total spot count + 10 * number of spotted regions)
Weighted SN: 118 192 139  (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): 93 97 112 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
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 73.1 (+4.1) 5.23
2013.10  132.1 131.2 85.6 75.0 (+1.9) 7.71
2013.11  148.3 145.1 77.6 75.4 (+0.4) 5.68
2013.12 147.7 143.1 90.3 (75.8 projected, +0.4) 4.68
2014.01 157.4 152.4 82.0 (76.4 projected, +0.6) 5.44
2014.02 170.3
(cycle peak)
166.3 102.8 (cycle peak) (76.2 projected, -0.2) 10.70
2014.03 149.9 148.5 92.2 (76.6 projected, +0.4) 4.88
2014.04 143.9 144.8 84.7 (75.8 projected, -0.8) 7.88
2014.05 129.7 132.9 75.2 (73.2 projected, -2.6) 5.75
2014.06 114.5 (1)    20.8 (2A) / 92.0 (2B) / 88.0 (2C) (70.5 projected, -2.7) (5.8)

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.