Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 10, 2015 at 06:45 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 9. Solar wind speed at SOHO ranged between 341 and 371 km/s.

Solar flux at 20h UTC on 2.8 GHz was 121.9 (decreasing 14.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 127.0. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.3). Three hour interval K indices: 12111111 (planetary), 13122312 (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 13 active regions using 2K resolution (SN: 221) and 8 active regions using 1K resolution (SN: 120) SDO images on the visible solar disk.

Region 12373 [N16W80] decayed slowly and quietly.
Region 12375 [S09W61] decayed slowly and quietly.
Region 12376 [N12W60] lost the leader spot and was quiet.
Region 12378 [S15W21] decayed slowly and quietly.
Region 12381 [N14W12] was mostly quiet and stable. The region has minor polarity intermixing and there is a low chance of a minor M class event.
Region 12383 [S06W22] decayed slowly and quietly.
Region 12384 [S18E51] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4590 [N23W24] was quiet and stable.
S4599 [S10W39] decayed slowly and quietly.
S4603 [S24W02] was quiet and stable.
New region S4606 [N07W39] emerged with several spots.
New region S4607 [S19E21] emerged with penumbra spots.
New region S4608 [N17E42] was observed with penumbra spots.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
           

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

Coronal mass ejections (CMEs)

July 7-9: 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 to fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet to active on July 10-11 due to effects from CH676 and quiet on July 12.

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 1 1 N16W81 0040 HSX HAX

 

12376 2015.06.28
2015.06.30
3 1   N12W70 0010 AXX AXX area: 0001

location: N12W60

12375 2015.06.28
2015.06.29
1 1 1 S09W62 0050 HSX HSX  
12379 2015.07.01
2015.07.03
3     S09W39 0010 BXO    

spotless

SWPC has adopted the spots of AR S4599

real location: S14W31

12378 2015.07.01
2015.07.02
2 7 3 S10W23 0020 HSX CRO

real location: S15W21

S4587 2015.07.02       N08W45          
12381 2015.07.03
2015.07.04
19 33 19 N14W11 0500 EKO FKO

area: 0690

S4590 2015.07.03   6   N23W24 0010   AXX  
12382 2015.07.04
2015.07.05
      S05W58           spotless
S4594 2015.07.04       N07E15            
12383 2015.07.06
2015.07.07
10 13 6 S06W24 0050 DSO DRI

 

12384 2015.07.07
2015.07.08
1 3 2 S17E47 0140 HSX HKX area: 0290

location: S18E51

S4599 2015.07.07   8 2 S10W39 0015   HRX  
S4600 2015.07.07       N09E30            
S4601 2015.07.07       N17W23            
S4602 2015.07.07       N09W04            
S4603 2015.07.07   1   S24W02 0001   AXX  
S4604 2015.07.08       S02E11          
S4606 2015.07.09   11 6 N07W39 0030   DRI    
S4607 2015.07.09   3   S19E21 0004   AXX    
S4608 2015.07.09   3   N17E42 0004   AXX    
Total spot count: 40 91 40  
Sunspot number: 120 221 120  (total spot count + 10 * number of spotted regions)
Weighted SN: 75 133 82  (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): 132 122 102 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 (121.6)   30.1 (2A) / 103.7 (2B) / 93.7 (2C) (74.4 projected, -3.6) (7.6)

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.