Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 2, 2015 at 05:40 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 (June 1, 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 1-20 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 1. Solar wind speed at SOHO ranged between 347 and 412 km/s. Wind speed increased slowly after 07 UT and temperature increased to a level normally observed during a coronal hole stream, this was likely the arrival of a low speed stream associated with CH674. No significant geomagnetic effects were observed.

Solar flux at 20h UTC on 2.8 GHz was 100.8 (decreasing 8.4 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 126.0. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.8). Three hour interval K indices: 21112211 (planetary), 21122321 (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 7 active regions using 2K resolution (SN: 139) and 6 active regions using 1K resolution (SN: 98) SDO images on the visible solar disk.

Region 12373 [N16E26] gained spots and remained quiet.
Region 12375 [S09E45] was quiet and stable.
Region 12376 [N12E46] was mostly quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S4581 [N11W12] was quiet and stable.
New region S4583 [S10W21] emerged with several spots.
New region S4585 [S14E74] rotated into view with penumbra spots.
New region S4586 [S15E84] 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)

June 29 - July 1: 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 southern hemisphere coronal hole (CH675) will rotate across the central meridian on July 1-2.

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 2-3. Effects from CH675 and a co-rotating interactive region could cause quiet to minor storm conditions on July 4-6.

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
S4564 2015.06.21       N16W56            
S4569 2015.06.25       S16W34         images/AR_S4569_20150630_2345.png  
12374 2015.06.26
2015.06.28
      N10W43            
12373 2015.06.27
2015.06.28
8 32 16 N16E29 0150 DSO CAI images/AR_12373_20150701_2345.png

location: N16E26

12376 2015.06.28
2015.06.30
10 22 13 N13E46 0150 EAI EAI location: N12E46
12375 2015.06.28
2015.06.29
1 3 2 S09E44 0080 HSX CAO area: 0110

location: S09E59

S4580 2015.06.28       S00W42            
S4581 2015.06.30   1   N11W12 0002   AXX  
S4583 2015.07.01   7 5 S10W21 0030   CRO    
S4585 2015.07.01   3 1 S14E74 0008   AXX    
S4586 2015.07.01   1 1 S15E84 0100   HSX    
Total spot count: 19 69 38  
Sunspot number: 49 139 98  (total spot count + 10 * number of spotted regions)
Weighted SN: 34 92 61  (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): 54 76 83 k * (sunspot number)
From 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 (109.6)   1.6 (2A) / 49 (2B) / 88.2 (2C) (74.4 projected, -3.6) (4.8)

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.