Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 29, 2015 at 05:55 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 28 under the influence of CME effects. Solar wind speed at SOHO ranged between 371 and 508 km/s.

Solar flux at 20h UTC on 2.8 GHz was 97.3 (decreasing 3.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 126.6. The Potsdam WDC planetary A index was 11 (STAR Ap - based on the mean of three hour interval ap indices: 11.1). Three hour interval K indices: 23322323 (planetary), 34433332 (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 9 active regions using 2K resolution (SN: 116) and 8 active regions using 1K resolution (SN: 95) SDO images on the visible solar disk.

Region 12371 [N14W86] rotated mostly out of view with only a tiny part of the easternmost spots visible at the end of the day.
New region 12373 [N16E67] rotated into view on June 27 and was numbered by SWPC the next day.
New region 12374 [N09W01] emerged on June 26 and was numbered by SWPC two days later when more flux emerged.

Spotted regions not numbered (or interpreted differently) by SWPC:

S4569
[S17E07] gained trailing spots while losing most of the leading spots.
S4573 [N15E53] was quiet and stable.
New region S4576 [S19W53] emerged early in the day with penumbra spots and decayed slowly late in the day.
New region S4577 [N13E83] rotated partly into view.
New region S4578 [S09E85] rotated into view.
New region S4580 [S00W03] was observed with a penumbra spot.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
           

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

Coronal mass ejections (CMEs)

June 26-28: 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 small southern hemisphere coronal hole (CH674) was in an Earth facing position on June 27. A recurrent southern hemisphere coronal hole will likely rotate across the central meridian on July 1-2.

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 mostly quiet on June 29-30 and July 1 with a chance of a few unsettled intervals on June 30 and July 1 if a high speed stream associated with CH674 arrives.

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
12371 2015.06.15
2015.06.16
3 2   N13W92 0130 CAO AXX  
S4563 2015.06.20       S09W54            
S4564 2015.06.21       N16W17            
S4568 2015.06.23       N32W43            
S4569 2015.06.25   3 1 S17E07 0008   BXO images/AR_S4569_20150628_2345.png  
12374 2015.06.26
2015.06.28
3 7 3 N08W01 0010 BXO CRO   area: 0020
12373 2015.06.27
2015.06.28
3 6 5 N15E67 0080 DSO CAO  
S4573 2015.06.27   2 1 N15E53 0005   AXX  
S4576 2015.06.28   1 1 S19W53 0005   AXX    
S4577 2015.06.28   3 2 N13E83 0090   DAO    
S4578 2015.06.28   1 1 S09E85 0070   HAX    
S4580 2015.06.28   1 1 S00W03 0003   AXX    
Total spot count: 9 26 15  
Sunspot number: 39 116 95  (total spot count + 10 * number of spotted regions)
Weighted SN: 19 44 33  (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): 23 41 52 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 (124.0)   74.7 (2A) / 80.0 (2B) / 57.3 (2C) (49.6 projected, -2.8) (13.3)

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.