Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 5, 2014 at 03:40 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 on June 4. Solar wind speed at SOHO ranged between 282 and 389 km/s.

Solar flux at 20h UTC on 2.8 GHz was 105.4 (decreasing 42.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 139.7. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.6). Three hour interval K indices: 12111112 (planetary), 21221222 (Boulder).

The background x-ray flux is at the class B3 level.

At the time of counting spots (see image time), spots were observed in 11 active regions using 2K resolution (SN: 171) and 10 active regions using 1K resolution (SN: 139) SDO images on the visible solar disk.

Region 12077 [S04E03] was mostly unchanged and produced 2 low level C flares.
Region 12078 [S18W26] was quiet and stable.
Region 12079 [N12E27] was quiet and stable.
Region 12080 [S12E47] gained several spots and could produce C flares.
New region 12081 [N05E33] rotated into view on June 1 and was noticed by SWPC 3 days later.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3499 [S12E39] decayed slightly and was quiet.
New region S3500 [S21W30] emerged early in the day close to AR 12078.
New region S3501 [S23E31] emerged with a penumbra spot.
New region S3502 [S12E25] emerged with penumbra spots.
New region S3503 [N17E54] emerged with penumbra spots.
New region S3504 [S12W48] emerged with penumbra spots.

C2+ Flares (GOES):

Magnitude Time (UTC) Location AR
C2.1 01:36   12077

Coronal mass ejections (CMEs)

June 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

An extension (CH621) of a large southern hemisphere coronal hole will likely rotate into an Earth facing position on June 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 fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on June 5-7.

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
12075 2014.05.23       S09W83        

plage

S3483 2014.05.29       S11W48           plage
S3484 2014.05.29       S13W36           plage
12077 2014.05.30 6 14 11 S05E03 0080 CSO CSO

area: 0180

12078 2014.05.30
2014.06.01
2 4 3 S19W27 0010 BXO CRO  
12079 2014.05.31
2014.06.01
1 8 4 N12E26 0090 HSX HSX area: 0200
S3492 2014.05.31       N12E01         plage
12081 2014.06.01
2014.06.04
1 1 1 N04E32 0010 AXX AXX  
S3495 2014.06.01       S10W14           plage
S3496 2014.06.02       N17E26           plage
12080 2014.06.02
2014.06.03
10 20 14 S12E43 0030 CRI DRI area: 0090
S3499 2014.06.03   3 1 S12E39 0004   AXX  
S3500 2014.06.04   1 1 S21W30 0010   HRX    
S3501 2014.06.04   1   S23E31 0003   AXX    
S3502 2014.06.04   2 1 S12E25 0005   BXO    
S3503 2014.06.04   3 1 N17E54 0010   BXO    
S3504 2014.06.04   4 2 S12W48 0014   BXO    
Total spot count: 20 61 39  
Sunspot number: 70 171 139  (total spot count + 10 * number of spotted regions)
Weighted SN: 33 80 58  (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): 42 60 76 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) 5.7
2014.06 105.3 (1)    8.5 (2A) / 63.8 (2B) / 88.4 (2C) (70.5 projected, -2.7) (4.9)

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.