Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 9, 2015 at 06:40 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 8. Solar wind speed at SOHO ranged between 346 and 405 km/s.

Solar flux at 20h UTC on 2.8 GHz was 128.9 (decreasing 11.0 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 126.9. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.9). Three hour interval K indices: 11111121 (planetary), 12212312 (Boulder).

The background x-ray flux is at the class B3 level.

At the time of counting spots (see image time), spots were observed in 14 active regions using 2K resolution (SN: 230) and 12 active regions using 1K resolution (SN: 173) SDO images on the visible solar disk.

Region 12373 [N16W66] decayed slowly and quietly.
Region 12375 [S09W48] decayed slowly and quietly.
Region 12376 [N12W57] decayed quickly and was quiet.
Region 12378 [S16W08] decayed slowly and quietly.
Region 12379 [S14W18] decayed slowly and quietly.
Region 12381 [N14E03] simplified magnetically and was quiet. Slow decay was observed in the trailing spot section.
Region 12383 [S06W09] was quiet and stable.
New region 12384 [S18E65] rotated into view on July 7 and was numbered the next day by SWPC.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4587 [N08W32] was quiet and stable.
S4590 [N22W16] reemerged with penumbra spots.
S4599 [S09W25] decayed quickly and was quiet.
S4603 [S15E12] was quiet and stable.
New region S4604 [S02E24] was observed with penumbra spots.
New region S4605 [S14W58] emerged with 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)

July 6-8: 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) was in 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 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 3 2 N16W67 0040 HSX CSO

 

12376 2015.06.28
2015.06.30
2 5 3 N12W55 0050 HSX CRO  
12375 2015.06.28
2015.06.29
1 2 2 S09W49 0050 HSX HAX  
12379 2015.07.01
2015.07.03
4 3 1 S11W24 0010 AXX BXO

SWPC data includes spots of AR S4599

location: S14W18

12378 2015.07.01
2015.07.02
4 13 7 S16W08 0050 HSX CAO

 

S4587 2015.07.02   3   N08W32 0015   AXX  
12381 2015.07.03
2015.07.04
28 28 19 N14E03 0550 EKO EKO

area: 0730

S4590 2015.07.03   3   N22W16 0005   BXO    
12380 2015.07.03
2015.07.04
      N09W84            
12382 2015.07.04
2015.07.05
      S05W43           spotless
S4594 2015.07.04       N07E28            
12383 2015.07.06
2015.07.07
9 16 10 S07W10 0010 BXO DRI SWPC area and classification not in accordance with imagery

area: 0060

12384 2015.07.07
2015.07.08
2 2 1 S18E62 0120 HSX HHX area: 0270

location: S18E65

S4599 2015.07.07   6 4 S09W25 0015   CRO  
S4600 2015.07.07       N09E43          
S4601 2015.07.07       N17W10          
S4602 2015.07.07       N09E09          
S4603 2015.07.07   1 1 S15E12 0004   AXX  
S4604 2015.07.08   3 2 S02E24 0007   AXX    
S4605 2015.07.08   3 1 S14W58 0016   BXO    
Total spot count: 51 91 53  
Sunspot number: 131 231 173  (total spot count + 10 * number of spotted regions)
Weighted SN: 81 135 124  (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): 144 127 147 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 (121.5)   26.2 (2A) / 101.6 (2B) / 94.4 (2C) (74.4 projected, -3.6) (8.0)

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.