Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 8, 2015 at 04:55 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 unsettled on June 7, increasingly under the influence of effects from CH671. Solar wind speed at SOHO ranged between 275 and 409 km/s.

Solar flux at 20h UTC on 2.8 GHz was 137.3 (decreasing 25.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 125.1. 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: 01111133 (planetary), 02223233 (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 10 active regions using 2K resolution (SN: 241) and 10 active regions using 1K resolution (SN: 170) SDO images on the visible solar disk.

Region 12356 [S16W72] was quiet and stable.
Region 12358 [S02W22] was quiet and stable.
Region 12360 [N16W03] gained area as new flux emerged. The region has polarity intermixing. C flares are possible, maybe even a minor M clas flare.
Region 12361 [N18E24] decayed slowly and was mostly quiet.
Region 12362 [N07E30] decayed slowly and was mostly quiet.
Region 12363 [N05W45] was quiet and stable.
Region 12364 [S05E50] was mostly quiet and stable.
Region 12365 [S13E49] was quiet and stable.
New region 12366 [N17E46] emerged on June 6 and developed slowly on June 7 when it was numbered by SWPC.

Spotted regions not numbered (or interpreted differently) by SWPC:
New region S4530 [N12E39] emerged with penumbra spots.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
           

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

Coronal mass ejections (CMEs)

June 5-7: 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 southern hemisphere coronal hole (CH671) was in an Earth facing position on June 3-5. Another recurrent southern hemisphere coronal hole (CH672) will likely rotate 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 active on June 8-9 due to effects from CH671, isolated minor storm intervals are possible. Quiet to unsettled is likely on June 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 overlays
Comment
SWPC Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12359 2015.05.26
2015.06.01
      S13W83          
12356 2015.05.27
2015.05.28
1 2 1 S16W72 0070 HSX CSO area: 0090
12357 2015.05.28
2015.05.29
      N09W76            
12358 2015.05.31 2 4 2 S03W21 0000 AXX AXX

area: 0010

S4518 2015.06.01       S18W40            
12360 2015.06.01
2015.06.03
13 53 28 N15W04 0140 EAC EAC images/AR_12360_20150607_2345.png images/AR_12360_20150606_2345.png beta-gamma
12361 2015.06.03
2015.06.04
7 30 15 N16E22 0080 DAI DAI beta-gamma
12362 2015.06.03
2015.06.04
8 14 9 N05E27 0140 DAO DAO area: 0210

location: N07E30

S4523 2015.06.03       S05W34            
12363 2015.06.04
2015.06.05
2 6 3 N04W45 0010 AXX CRO  
S4525 2015.06.04       S08W56            
S4526 2015.06.04       S12E12            
12365 2015.06.05
2015.06.06
5 9 5 S13E48 0090 CSO DAO area: 0150
12364 2015.06.05
2015.06.06
5 11 3 S05E50 0010 BXO BXO area: 0025
12366 2015.06.06
2015.06.07
3 10 3 N17E45 0020 CRO CRO  
S4530 2015.06.07   2 1 N12E39 0006   BXO    
Total spot count: 46 141 70  
Sunspot number: 136 241 170  (total spot count + 10 * number of spotted regions)
Weighted SN: 74 172 101  (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): 82 84 94 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 (117.7)   19.4 (2A)/ 83.1 (2B) / 72.7 (2C) (49.6 projected, -2.8) (3.4)

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.