Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 6, 2014 at 15:35 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 unsettled on June 5. Solar wind speed at SOHO ranged between 335 and 348 km/s.

Solar flux at 20h UTC on 2.8 GHz was 110.5 (decreasing 41.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 139.3. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 5.9). Three hour interval K indices: 11121123 (planetary), 22122323 (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 10 active regions using 2K resolution (SN: 180) and 8 active regions using 1K resolution (SN: 129) SDO images on the visible solar disk.

Region 12077 [S03W11] decayed slowly and quietly.
Region 12079 [N12E13] was quiet and stable.
Region 12080 [S12E32] developed slowly and quietly.
Region 12081 [N05E19] was quiet and stable.
New region 12082 [N17E39] emerged on June 4 and developed further on June 5 when the region was numbered by SWPC.
New region 12083 [S12W62] emerged on June 4 and developed slowly on June 5.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3500 [S21W44] was quiet and stable. SWPC is including the spot in now spotless AR 12078.
S3501 [S23E29] was quiet and stable.
New region S3505 [S15E59] emerged with a penumbra spot.
New region S3506 [S20E39] emerged with penumbra spots.

C2+ Flares (GOES):

Magnitude Time (UTC) Location AR
       

Coronal mass ejections (CMEs)

June 3 and 5: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
June 4: A large filament eruption in the southeast quadrant during the evening was associated with an asymmetric full halo CME.

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.

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 poor to fair.

Forecast

The geomagnetic field is expected to be quiet on June 6. On June 7 and 8 the CME observed on June 4 will likely reach Earth and cause unsettled to active conditions.

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
S3484 2014.05.29       S13W49           plage
12077 2014.05.30 5 5 4 S05W12 0070 CSO HSX

area: 0160

12078 2014.05.30
2014.06.01
1     S20W43 0000 AXX     spotless

real location: S19W40

12079 2014.05.31
2014.06.01
1 12 7 N12E13 0090 HSX CSO area: 0180
S3492 2014.05.31       N12W12           plage
12081 2014.06.01
2014.06.04
1 5 3 N05E19 0000 AXX AXX  
S3495 2014.06.01       S10W27           plage
S3496 2014.06.02       N17E13           plage
12080 2014.06.02
2014.06.03
14 28 18 S12E32 0120 DAO DAI area: 0240
S3499 2014.06.03       S12E26         plage
S3500 2014.06.04   1   S21W44 0002   AXX  
S3501 2014.06.04   2 2 S23E29 0008   BXO  
S3502 2014.06.04       S12E12         plage
12082 2014.06.04
2014.06.05
5 18 12 N17E40 0020 CRI DAC area: 0110
12083 2014.06.04
2014.06.05
5 6 2 S12W62 0010 BXO CRO area: 0025
S3505 2014.06.05   1   S15E59 0003   AXX    
S3506 2014.06.05   2 1 S20E39 0006   BXO    
Total spot count: 32 80 49  
Sunspot number: 102 180 129  (total spot count + 10 * number of spotted regions)
Weighted SN: 50 103 72  (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): 61 63 71 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
2014.06 106.3 (1)    11.9 (2A) / 71.4 (2B) / 87.3 (2C) (70.5 projected, -2.7) (5.1)

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 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.