Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 12, 2015 at 06:15 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 to active on July 11 under the influence of a high speed stream from CH676. Solar wind speed at SOHO ranged between 453 and 629 km/s.

Solar flux at 20h UTC on 2.8 GHz was 120.2 (decreasing 11.5 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 127.0. The Potsdam WDC planetary A index was 21 (STAR Ap - based on the mean of three hour interval ap indices: 20.9). Three hour interval K indices: 44433243 (planetary), 55533333 (Boulder).

The background x-ray flux is at the class B4 level.

At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 154) and 7 active regions using 1K resolution (SN: 100) SDO images on the visible solar disk.

Region 12378 [S15W47] decayed slowly and quietly.
Region 12381 [N14W38] decayed slowly and was quiet.
Region 12383 [S07W52] decayed slowly and quietly.
Region 12384 [S18E25] displayed fragmentation of the largest penumbra and gained some spots.
Region 12385 [N07W67] decayed and was mostly quiet.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4599 [S10W66] was quiet and stable.
S4607 [S19W08] reemerged with penumbra spots.
S4610 [S04E64] was quiet and stable.
New region S4612 [N10E84] rotated into view.

C2+ flares:

Magnitude Peak time (UTC) Location AR Recorded by Comment
           

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

Coronal mass ejections (CMEs)

July 9-11: 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 fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on July 12 due to effects from CH676 and quiet on July 13-14.

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
12375 2015.06.28
2015.06.29
1     S09W89 0040 HAX     rotated out of view
12379 2015.07.01
2015.07.03
      S11W66          

real location: S14W57

12378 2015.07.01
2015.07.02
1 6 1 S16W49 0010 AXX BXO

 

12381 2015.07.03
2015.07.04
11 16 9 N14W38 0380 FKO FKO

area: 0570

S4590 2015.07.03       N23W50            
12382 2015.07.04
2015.07.05
      S05W88            
S4594 2015.07.04       N07W11            
12383 2015.07.06
2015.07.07
2 2   S06W52 0010 BXO AXX

 

12384 2015.07.07
2015.07.08
5 19 8 S18E23 0180 CAO CAO beta-gamma

area: 0240

S4599 2015.07.07   1   S10W66 0003   AXX  
S4600 2015.07.07       N09E04            
S4601 2015.07.07       N17W49            
S4602 2015.07.07       N09W30            
S4603 2015.07.07       S24W28            
S4604 2015.07.08       S02W15            
12385 2015.07.09
2015.07.10
11 15 8 N08W68 0110 DAO DAI  
S4607 2015.07.09   2 2 S19W08 0006   AXX    
S4608 2015.07.09       N17E16          
S4610 2015.07.10   2 1 S04E64 0012   HRX  
S4612 2015.07.11   1 1 N10E84 0160   HSX    
Total spot count: 31 64 30  
Sunspot number: 91 154 100  (total spot count + 10 * number of spotted regions)
Weighted SN: 56 92 58  (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): 100 85 85 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 (122.1)   37.0 (2A) / 104.4 (2B) / 91.8 (2C) (74.4 projected, -3.6) (8.9)

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.