Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 7, 2015 at 06:15 UT. Updates on July 8 will likely be only partial and may be late.

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 (July 3, 2015)
Solar cycle Solar cycles 23-24 (July 1, 2015) Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)
  Cycle 24 progress (July 1, 2015) Noon SDO sunspot count 1K Reference: 4K (large file) (*)
  Solar cycles 1-23 - Solar Cycles 1-24 overview (new) POES auroral activity level October 2009 - December 2012
  Comparison of cycles 21, 22, 23 and 24 (July 1, 2015) 3rd SSN Workshop, Tucson, 2013
  Comparison of cycles 12, 13, 14, 16 and 24 (July 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 July 6 under the influence of a high speed stream associated with CH675. Solar wind speed at SOHO ranged between 426 and 522 km/s.

Solar flux at 20h UTC on 2.8 GHz was 133.4 (increasing 2.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 126.3. The Potsdam WDC planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 9.6). Three hour interval K indices: 43311121 (planetary), 35321321 (Boulder).

The background x-ray flux is at the class B7 level.

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 216) and 8 active regions using 1K resolution (SN: 145) SDO images on the visible solar disk.

Region 12373 [N16W40] decayed slowly and quietly.
Region 12375 [S10W22] was quiet and stable.
Region 12376 [N12W27] decayed slowly and quietly.
Region 12378 [S17E18] decayed slowly and quietly.
Region 12379 [S13E07] decayed slowly and quietly.
Region 12381 [N14E30] developed further and has polarity intermixing. A magnetic delta formed early in the day in a southern central penumbra, however, the delta disappeared late in the day.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4587 [N06W08] was quiet and stable.
S4590 [N23E08] was quiet and stable.
New region S4597 [S07E18] emerged with a penumbra spot.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
C2.5 07:50 N17E42 12381 GOES15  
M1.0 08:44 N17E42 12381 GOES15 C8.8 @ SDO/EVE
C2.0 11:20 N17E40 12381 SDO/EVE C1.9 @ GOES15
C5.7 11:42 N17E42 12381 GOES15  
C2.2 15:31 behind SE limb   GOES15  
C3.5 16:22 N16E39 12381 GOES15  
C4.9 17:02 N17E37 12381 GOES15  
M1.7 20:40   12381 GOES15  
C3.0 21:33 N18E36 12381 SDO/EVE  

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

Coronal mass ejections (CMEs)

July 4-6: 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 (CH676) will likely rotate into an Earth facing position on July 7-8.

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 July 7-9. Effects from CH676 could cause some unsettled and active intervals on July 10-11.

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
12373 2015.06.27
2015.06.28
3 14 8 N15W40 0080 CSO CSO images/AR_12373_20150706_2345.png images/AR_12373_20150705_2345.png

 

12376 2015.06.28
2015.06.30
9 31 13 N12W24 0050 CAO CAO  
12375 2015.06.28
2015.06.29
2 4 2 S11W22 0060 HSX CSO  
12379 2015.07.01
2015.07.03
7 14 8 S15E07 0030 DRO CRO

location: S13E07

12378 2015.07.01
2015.07.02
3 8 5 S17E18 0060 HAX CAO

area: 0090

S4587 2015.07.02   2   N05W08 0005   BXO  
12381 2015.07.03
2015.07.04
14 50 26 N14E31 0350 EKC EKC beta-gamma

area: 0700

S4590 2015.07.03   4 2 N23E08 0009   BXO  
12380 2015.07.03
2015.07.04
      N09W56          
12382 2015.07.04
2015.07.05
1     S05W13 0000 AXX     spotless
S4594 2015.07.04       N07E54            
S4595 2015.07.05       S17W55          
S4597 2015.07.06   1 1 S07E18 0003   AXX    
Total spot count: 39 128 65  
Sunspot number: 109 218 145  (total spot count + 10 * number of spotted regions)
Weighted SN: 72 161 98  (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): 120 120 123 k * (sunspot number)
As of July 1, 2015: k = 1.1 for SWPC, k = 0.55 for MSN 2K, k = 0.85 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO) (4)
Smoothed sunspot number (4) Average ap
(3)
Measured 1 AU
2014.01 157.4 152.4 117.0 109.3 (+1.7) 5.44
2014.02 170.3
(cycle peak)
166.3 146.1 (cycle peak) 110.5 (+1.2) 10.70
2014.03 149.9 148.5 128.7 114.3 (+3.8) 4.88
2014.04 143.9 144.8 112.5 116.4 (+2.1) (solar max) 7.88
2014.05 129.7 132.9 112.5 115.0 (-1.4) 5.75
2014.06 122.0 125.8 102.9 114.1 (-0.9) 6.72
2014.07 137.4 141.8 100.2 112.8 (-1.3) 4.50
2014.08 124.7 127.9 106.9 108.7 (-4.1) 7.71
2014.09 146.6 148.1 130.0 102.5 (-6.2) 9.78
2014.10 153.4 152.9 90.0 98.0 (-4.5) 8.96
2014.11 154.8 151.4 103.6 95.7 (-2.3) 9.33
2014.12 158.7 153.8 112.9 93.3 (-2.4) 11.24
2015.01 141.9 137.3 97.6 (91.1 projected, -2.2) 9.46
2015.02 129.1 126.0 67.8 (89.8 projected, -1.3) 9.92
2015.03 125.9 124.6 56.8 (87.3 projected, -2.5) 16.14
2015.04 128.8 129.7 78.0 (83.9 projected, -3.4) 10.73
2015.05 120.0 122.6 90.0 (81.3 projected, -2.6) 8.29
2015.06 122.3 126.1 68.3 (78.0 projected, -3.3) 12.8
2015.07 (118.5)   18.2 (2A) / 94 (2B) / 91.9 (2C) (74.4 projected, -3.6) (9.4)

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).
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.
4) Updated to new data set from WDC-SILSO on July 1, 2015

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 Universal Time. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.