Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 12, 2014 at 06:10 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 11. Solar wind speed at SOHO ranged between 335 and 368 km/s.

Solar flux at 20h UTC on 2.8 GHz was 166.3 (increasing 22.8 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 140.1. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.1). Three hour interval K indices: 11211122 (planetary), 11222322 (Boulder).

The background x-ray flux is at the class B9 level.

At the time of counting spots (see image time), spots were observed in 10 active regions using 2K resolution (SN: 270) and 9 active regions using 1K resolution (SN: 186) SDO images on the visible solar disk.

Region 12107 [S19W80] was quiet and stable.
Region 12108 [S07W67] was quiet and stable.
Region 12109 [S08W46] decayed slowly and was mostly quiet.
Region 12111 [N06W29] was quiet and stable. The region has minor polarity intermixing.
Region 12113 [N07E09] gained small spots and could produce C flares.
Region 12114 [S20E28] was quiet and stable.
Region 12116 [S28E30] decayed slowly and quietly.
New region 12117 [N08E17] was split off from AR 12113 as new negative polarity flux emerged.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3622 [S25W25] was quiet and stable.
S3634 [S04W59] developed further and could soon merge with AR 12108.

C2+ Flares (GOES):

Magnitude Peak time (UTC) Location AR
C4.6 00:44 S06W32 12109
C2.5 23:13   12113
C2.3 23:47   12117

Coronal mass ejections (CMEs)

July 11: 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.
July 9: A partial halo CME was observed after the M1 flare in AR 12113. There is a minor chance that a weak extension could reach Earth on July 12.

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 to fair.

Forecast

The geomagnetic field is expected to be quiet on July 12-14. There is a slight chance of CME effects on July 12-13.

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
12104 2014.06.28 2     S12W92 0050 DSO     rotated out of view
12107 2014.06.28
2014.06.29
1 1 1 S19W80 0130 HSX HHX  

area: 0270

12106 2014.06.29 2     N14W90 0030 CAO     rotated out of view
12108 2014.06.30
2014.07.01
15 21 13 S07W64 0560 EKC EKC

area: 0930

location: S07W67

12109 2014.07.01
2014.07.02
12 27 12 S08W47 0530 DKC DKC beta-gamma

area: 0850

12110 2014.07.02
2014.07.03
      S15W61           plage
12111 2014.07.03
2014.07.04
9 26 15 N06W30 0050 CAO DAI  
S3614 2014.07.04       N06W18           plage
S3618 2014.07.05       N18W25           plage
12113 2014.07.06 10 27 19 N07E12 0030 CRO DRI

location: N07E09

12115 2014.07.06
2014.07.08
      N08W77           plage
S3622 2014.07.06   3   S25W25 0008   AXX  
S3623 2014.07.06       S18W39           plage
12114 2014.07.07
2014.07.08
7 26 13 S21E26 0080 DAO DRI location: S20E28
12116 2014.07.08
2014.07.10
1 6 4 S29E29 0010 AXX CRO  
S3631 2014.07.08       S15E23           plage
S3632 2014.07.08       S16W11           plage
S3633 2014.07.08       N15W06           plage
S3634 2014.07.10   16 8 S4W59 0100   DAI  
S3635 2014.07.10       S21W45         plage
12117 2014.07.11 7 17 11 N10E17 0020 CAO DRO   area: 0060
Total spot count: 66 170 96  
Sunspot number: 166 270 186  (total spot count + 10 * number of spotted regions)
Weighted SN: 119 222 148  (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 95 102 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
2014.07 183.8 (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.