Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 8, 2015 at 02:20 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 (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 on July 7. Solar wind speed at SOHO ranged between 378 and 463 km/s.

Solar flux at 20h UTC on 2.8 GHz was 132.6 (decreasing 2.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 126.7. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.1). Three hour interval K indices: 20111112 (planetary), 31122212 (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 14 active regions using 2K resolution (SN: 283) and 14 active regions using 1K resolution (SN: 218) SDO images on the visible solar disk.

Region 12373 [N16W53] decayed slowly and quietly.
Region 12375 [S10W35] was quiet and stable.
Region 12376 [N12W42] decayed slowly and quietly.
Region 12378 [S17E05] was quiet and stable.
Region 12379 [S14W07] decayed slowly and quietly.
Region 12381 [N14E17] matured somewhat as the largest areas of positive and negative magnetic polarity drifted apart. A small magnetic delta formed in the trailing spot section.
New region 12383 [S07E05] emerged on July 6 and was numbered by SWPC the next day.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4587 [N09W17] was quiet and stable.
New region S4598 [S19E78] rotated into view with a large symmetrical spot.
New region S4599 [S11W10] emerged with several spots immediately to the northwest of AR 12379.
New region S4600 [N09E56] emerged with penumbra spots.
New region S4601 [N17E03] emerged with a penumbra spot.
New region S4602 [N09E22] emerged with a penumbra spot.
New region S4603 [S16E25] was observed with a penumbra spot.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
C2.7/1F 03:47 N14E32 12381 GOES15  

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

Coronal mass ejections (CMEs)

July 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 trans equatorial coronal hole (CH676) will 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.

Forecast

The geomagnetic field is expected to be quiet on July 8-9. 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
1 5 3 N16W55 0050 HSX HSX images/AR_12373_20150706_2345.png

 

12376 2015.06.28
2015.06.30
8 31 11 N12W38 0060 CAO DAO  
12375 2015.06.28
2015.06.29
1 5 4 S10W36 0050 HSX CSO  
12379 2015.07.01
2015.07.03
7 9 4 S13W07 0020 CRO BXO

 

12378 2015.07.01
2015.07.02
3 17 5 S17E03 0050 HSX CAO

 

S4587 2015.07.02   7 4 N09W17 0015   AXX  
12381 2015.07.03
2015.07.04
25 40 26 N14E17 0450 EKC EKC beta-gamma-delta

area: 0900

S4590 2015.07.03       N23W05          
12380 2015.07.03
2015.07.04
      N09W70            
12382 2015.07.04
2015.07.05
      S05W28           spotless
S4594 2015.07.04       N07E41            
12383 2015.07.06
2015.07.07
3 15 8 S06E04 0020 DRO DRI  
S4598 2015.07.07   1 1 S19E78 0270   HHX    
S4599 2015.07.07   8 7 S11W10 0045   DRI    
S4600 2015.07.07   2 2 N09E56 0008   BXO    
S4601 2015.07.07   1 1 N17E03 0004   AXX    
S4602 2015.07.07   1 1 N09E22 0004   AXX    
S4603 2015.07.07   1 1 S16E25 0004   AXX    
Total spot count: 48 143 78  
Sunspot number: 118 283 218  (total spot count + 10 * number of spotted regions)
Weighted SN: 79 189 124  (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): 130 156 185 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 (120.5)   22.0 (2A) / 97.4 (2B) / 93.2 (2C) (74.4 projected, -3.6) (8.6)

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.