Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 13, 2014 at 05:50 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update July 1, 2014)] [Cycle 24 progress (last update July 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update July 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update July 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update July 5, 2014)]

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated June 4, 2014]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet on July 12. Solar wind speed at SOHO ranged between 314 and 380 km/s.

Solar flux at 20h UTC on 2.8 GHz was 145.0 (increasing 14.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 140.3. 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: 12212100 (planetary), 22323422 (Boulder).

The background x-ray flux is at the class B6 level.

At the time of counting spots (see image time), spots were observed in 7 active regions using 2K resolution (SN: 188) and 7 active regions using 1K resolution (SN: 133) SDO images on the visible solar disk.

Region 12108 [S07W79] merged with AR S3634 and could produce an M class flare while near the southwest limb today and tomorrow.
Region 12109 [S08W59] produced a few low level C flares and was mostly unchanged.
Region 12111 [N07W42] decayed slowly and quietly.
Region 12113 [N08W04] was mostly quiet and stable.
Region 12114 [S20E15] was quiet and stable.
Region 12117 [N08E02] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
New region S3637 [S12W51] emerged with penumbra spots.

C2+ Flares (GOES):

Magnitude Peak time (UTC) Location AR
C2.5 07:14 S09W47 12109
C4.6 14:08   12108

Coronal mass ejections (CMEs)

July 11-12: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
July 10: A partial halo CME was observed after a filament eruption near the southwest limb. The CME has only a minor chance of causing geomagnetic effects.

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

No signficant coronal holes are currently in or near Earth facing positions.

Coronal hole map

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 13-15. There is a slight chance of CME effects on July 13.

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 overlay
Comment
SWPC Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12107 2014.06.28
2014.06.29
1     S19W93 0090 HSX     rotated out of view
12108 2014.06.30
2014.07.01
15 14 11 S07W77 0600 EKC EKC

area: 0850

12109 2014.07.01
2014.07.02
19 15 6 S08W60 0540 DHC CKO

area: 0770

12110 2014.07.02
2014.07.03
      S15W75           plage
12111 2014.07.03
2014.07.04
9 15 7 N06W45 0050 DAO DRO  
S3614 2014.07.04       N06W31           plage
S3618 2014.07.05       N18W38           plage
12113 2014.07.06 8 23 12 N07W04 0060 CSO DRI

 

S3622 2014.07.06       S25W38         plage
S3623 2014.07.06       S18W52           plage
12114 2014.07.07
2014.07.08
8 35 17 S20E13 0070 CSI DRI  
12116 2014.07.08
2014.07.10
1     S28E18 0000 AXX     spotless
S3631 2014.07.08       S15E10           plage
S3632 2014.07.08       S16W24           plage
S3633 2014.07.08       N15W19           plage
S3634 2014.07.10       S04W72         merged with AR 12108
S3635 2014.07.10       S21W58           plage
12117 2014.07.11 4 13 7 N09E05 0010 CAO DRO location: N08E02
S3637 2014.07.12   3 3 S12W51 0012   BXO    
Total spot count: 65 118 63  
Sunspot number: 145 188 133  (total spot count + 10 * number of spotted regions)
Weighted SN: 110 150 95  (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): 87 66 73 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for MSN 2K, k = 0.55 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number Average ap
(3)
Measured 1 AU
2013.02 104.3 101.8 38.0 58.4 (-0.3) 6.11
2013.03 111.3 110.2 57.9 57.5 (-0.9) 10.56
2013.04 124.8 125.9 72.4 57.9 (+0.4) 5.40
2013.05 131.4 134.3 78.7 59.9 (+2.0) 9.73
2013.06 110.1 113.7 52.5 62.6 (+2.7) 12.60
2013.07 115.5 119.3 57.0 65.5 (+2.9) 9.47
2013.08 114.6 118.3 66.0 69.0 (+3.5) 8.27
2013.09 102.6 103.7 36.9 73.1 (+4.1) 5.23
2013.10  132.1 131.2 85.6 75.0 (+1.9) 7.71
2013.11  148.3 145.1 77.6 75.4 (+0.4) 5.68
2013.12 147.7 143.1 90.3 76.0 (+0.6) 4.68
2014.01 157.4 152.4 81.8 (78.2 projected, +2.2) 5.44
2014.02 170.3
(cycle peak)
166.3 102.3 (cycle peak) (79.7 projected, +1.5) 10.70
2014.03 149.9 148.5 91.9 (80.5 projected, +0.8) 4.88
2014.04 143.9 144.8 84.7 (79.7 projected, -0.8) 7.88
2014.05 129.7 132.9 75.2 (77.1 projected, -2.6) 5.75
2014.06 122.0 125.8 71.0 (74.5 projected, -2.6) 6.72
2014.07 180.6 (1)   67.5 (2A) / 190.3 (2B) / 98.2 (2C) (71.5 projected, -3.0) (4.9)

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). The official WDC-SILSO international sunspot number is typically 30-50% lower. 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.

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 the UTC day. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.