Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 13, 2015 at 07:30 UT.

Charts (* = updated daily) Data and archive
  Solar wind (*) Solar and geomagnetic data - last month (*)
  Electron fluence (*) Archived daily reports and monthly data from 2003.01 (June 1, 2015)
Solar cycle Solar cycles 23-24 (June 1, 2015) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24 progress (June 1, 2015) Noon SDO sunspot count 1K Reference: 4K (large file) (*)
  Solar cycles 1-20 POES auroral activity level October 2009 - December 2012
  Comparison of cycles 21, 22, 23 and 24 (June 1, 2015) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 10, 12, 13, 14, 16 and 24 (June 1, 2015) 4th SSN Workshop, Locarno, 2014
  Solar polar fields vs solar cycles (June 8, 2015)  

Recent activity

The geomagnetic field was quiet on June 12. Solar wind speed at SOHO ranged between 439 and 518 km/s. A weak disturbance was observed arriving at ACE near 13h UT, possibly related to CH672.

Solar flux at 20h UTC on 2.8 GHz was 136.7 (increasing 5.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 126.3. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 5.8). Three hour interval K indices: 11112222 (planetary), 22213322 (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 16 active regions using 2K resolution (SN: 264) and 10 active regions using 1K resolution (SN: 149) SDO images on the visible solar disk.

Region 12360 [N15W70] developed further and has a magnetic delta structure in the central parts. A major flare is possible.
Region 12361 [N20W41] decayed slowly and quietly.
Region 12362 [N07W36] decayed slowly and quietly.
Region 12364 [S04W17] reemerged with a penumbra spot.
Region 12365 [S12W19] was quiet and has polarity intermixing. C class flaring is possible.
Region 12366 [N18W20] was quiet and stable.
Region 12367 [S20E59] gained penumbral area and produced some C flares. A minor M class flare is possible.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4530 [N10W24] was quiet and stable.
S4535 [S06W37] developed slowly and quietly
New region S4540 [N06E70] rotated into view.
New region S4541 [N16W17] was split off from AR 12360 and developed slowly.
New region S4542 [N11E05] was observed with a penumbra spot.
New region S4543 [S08E20] was observed with penumbra spots.
New region S4544 [S18W20] emerged with penumbra spots.
New region S4545 [N18E51] emerged with penumbra spots.
New region S4546 [S33W39] was observed with a penumbra spot.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
C2.2 00:50 N14W58 12360 GOES15  
C4.1/1F 02:06 N15W58 12360 GOES15 C5.1 @ SDO/EVE
C2.2/1F 07:21 S16E72 12367 GOES15  
C2.9 11:58 N12W63 12360 GOES15 simultaneous event in AR 12367
C3.9 15:34   12367 GOES15 attributed to AR 12360 by SWPC
C8.7 23:48 N14W73 12360 GOES15  

Flare activity according to SDO/EVE/ESP XRS-B proxy

Coronal mass ejections (CMEs)

June 10-12: No obviously Earth directed CMEs were observed.

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 (CH672) rotated across the central meridian on June 10-11.

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 to active on June 13-14 with a chance of minor storm intervals due to effects from CH672 and quiet to unsettled on June 15.

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 overlays
Comment
SWPC Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12360 2015.06.01
2015.06.03
16 19 11 N15W68 0220 EAC EKC beta-gamma-delta

area: 0520

12361 2015.06.03
2015.06.04
  4   N18W46 0010   BXO location: N20W41
12362 2015.06.03
2015.06.04
3 14 4 N08W39 0020 CRO CRO

location: N07W36

S4526 2015.06.04       S12W53            
12365 2015.06.05
2015.06.06
10 16 8 S13W18 0140 CAO CAO

beta-gamma

12364 2015.06.05
2015.06.06
  1   S07W19 0002   AXX  

 

12366 2015.06.06
2015.06.07
8 11 6 N17W20 0050 DAI DRO  
S4530 2015.06.07   2   N10W24 0007   AXX  
S4531 2015.06.08       S08W06          
S4532 2015.06.09       N07W24            
S4533 2015.06.09       S32E11            
S4534 2015.06.09       S22W40            
S4535 2015.06.09   3 2 S06W37 0017   CRO  
S4536 2015.06.10       S15W54            
12367 2015.06.10
2015.06.11
9 15 8 S18E58 0200 DAO DAI beta-gamma

area: 0440

location: S20E59

S4538 2015.06.11       N18W08          
S4539 2015.06.11       S10E53          
S4540 2015.06.12   2 2 N06E70 0009   AXX    
S4541 2015.06.12   9 5 N16W17 0060   DAO   split off from AR 12366
S4542 2015.06.12   1 1 N11E05 0004   AXX    
S4543 2015.06.12   2   S08E20 0005   AXX    
S4544 2015.06.12   2 2 S18W20 0007   BXO    
S4545 2015.06.12   2   N18E51 0004   BXO    
S4546 2015.06.12   1   S33W39 0002   AXX    
Total spot count: 46 104 49  
Sunspot number: 96 264 149  (total spot count + 10 * number of spotted regions)
Weighted SN: 69 138 83  (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): 58 92 82 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
2014.01 157.4 152.4 81.8 77.3 (+1.3) 5.44
2014.02 170.3
(cycle peak)
166.3 102.3 (cycle peak) 78.4 (+1.1) 10.70
2014.03 149.9 148.5 91.9 80.8 (+2.4) 4.88
2014.04 143.9 144.8 84.7 81.9 (+1.1) (solar max) 7.88
2014.05 129.7 132.9 75.2 80.5 (-1.4) 5.75
2014.06 122.0 125.8 71.0 79.7 (-0.8) 6.72
2014.07 137.4 141.8 72.5 78.5 (-1.2) 4.50
2014.08 124.7 127.9 74.7 75.5 (-3.0) 7.71
2014.09 146.6 148.1 87.6 70.8 (-4.7) 9.78
2014.10 153.4 152.9 60.6 67.3 (-3.5) 8.96
2014.11 154.8 151.4 70.1 65.4 (-1.9) 9.33
2014.12 158.7 153.8 78.0 (63.5 projected, -1.9) 11.24
2015.01 141.9 137.3 67.0 (61.3 projected, -2.2) 9.46
2015.02 129.1 126.0 44.8 (59.6 projected, -1.7) 9.92
2015.03 125.9 124.6 38.4 (57.2 projected, -2.4) 16.14
2015.04 128.8 129.7 54.4 (54.6 projected, -2.6) 10.73
2015.05 120.0 122.6 58.8 (52.4 projected, -2.2) 8.29
2015.06 (125.1)   37.1 (2A)/ 92.7 (2B) / 66.8 (2C) (49.6 projected, -2.8) (7.9)

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.