Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 15, 2015 at 06:00 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 to active on June 14 under the influence of a high speed stream associated with CH672. Solar wind speed at SOHO ranged between 434 and 587 km/s.

Solar flux at 20h UTC on 2.8 GHz was 131.7 (increasing 16.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 126.8. The Potsdam WDC planetary A index was 15 (STAR Ap - based on the mean of three hour interval ap indices: 15.3). Three hour interval K indices: 43342233 (planetary), 43452322 (Boulder).

The background x-ray flux is at the class B6 level.

At the time of counting spots (see image time), spots were observed in 17 active regions using 2K resolution (SN: 269) and 13 active regions using 1K resolution (SN: 180) SDO images on the visible solar disk.

Region 12362 [N07W63] decayed slowly and quietly.
Region 12364 [S05W43] was quiet and stable.
Region 12365 [S12W45] decayed slowly and quietly.
Region 12366 [N18W50] decayed slowly and quietly.
Region 12367 [S20E31] gained spots and became compact. The region has minor polarity intermixing and could produce C and minor M class flares.
Region 12368 [S05W65] developed slowly and quietly.
Region 12369 [N06E48] was quiet and stable.
New region 12370 [N18E24] emerged on June 12 and was numbered 2 days later by SWPC.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4531 [S10W13] reemerged with penumbra spots.
S4541 [N16W42] decayed quickly and quietly.
S4543 [S05E26] was quiet and stable.
S4544 [S18W47] decayed slowly and quietly.
S4548 [N08W08] decayed slowly and quietly.
New region S4550 [S18W12] emerged with penumbra spots.
New region S4551 [N16W11] was observed with a penumbra spot.
New region S4552 [S07W58] emerged with a penumbra spot.
New region S4553 [S22E17] emerged with penumbra spots.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
C2.4 00:42 N15W85 12360 SDO/EVE  
M2.0 00:59 N14W73 12360 GOES15 SDO/AIA location: N16W86
C5.9 04:17   12360 GOES15 attributed to AR 12365 by SWPC. SDO/AIA location: N14W90
C2.7 (LDE) 08:49   12360 GOES15  
C2.3 11:12 N13W90 12360 SDO/EVE C1.9 @ GOES15.

Flare activity (SDO/EVE/ESP XRS-B proxy)

Coronal mass ejections (CMEs)

June 12-14: 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 fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on June 15 and quiet on June 16-17.

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: 0-30% 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
2     N15W91 0060 CAO    

rotated out of view

12361 2015.06.03
2015.06.04
      N18W74         location: N21W61
12362 2015.06.03
2015.06.04
1 1 1 N07W63 0010 HRX AXX

area: 0005

12365 2015.06.05
2015.06.06
9 12 6 S15W47 0100 CAO CAO

SWPC is incorrectly including AR S4544 in this region

location: S12W47

12364 2015.06.05
2015.06.06
  1 1 S07W49 0004   AXX

location: S05W43

12366 2015.06.06
2015.06.07
6 3 1 N16W45 0010 BXO BXO  
S4531 2015.06.08   3 1 S08W32 0009   BXO  
S4532 2015.06.09       N07W50            
S4533 2015.06.09       S32W15            
12368 2015.06.09
2015.06.13
4 3 3 S06W65 0010 BXO BXO  
12367 2015.06.10
2015.06.11
15 36 20 S20E34 0340 EKC EKC

beta-gamma

area: 0570

location: S20E31

S4538 2015.06.11       N18W34            
S4539 2015.06.11       S10E27            
12369 2015.06.12
2015.06.13
  4 1 N06E40 0010   BXO  
S4541 2015.06.12   4 2 N16W42 0010   BXO  
S4542 2015.06.12       N11W21            
S4543 2015.06.12   1   S16E07 0003   AXX  
S4544 2015.06.12   6 3 S18W47 0013   BXO  
12370 2015.06.12
2015.06.14
10 16 9 N18E24 0020 CRI DRI area: 0050
S4548 2015.06.13   3   N08W08 0006   AXX  
S4550 2015.06.14   2 1 S18W12 0006   BXO    
S4551 2015.06.14   1 1 N16W11 0003   AXX    
S4552 2015.06.14   1   S07W58 0001   AXX    
S4553 2015.06.14   2   S22E17 0003   BXO    
Total spot count: 47 99 50  
Sunspot number: 117 269 180  (total spot count + 10 * number of spotted regions)
Weighted SN: 73 117 68  (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): 70 94 99 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 (126.4)   44.2 (2A)/ 94.7 (2B) / 65.1 (2C) (49.6 projected, -2.8) (8.3)

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.