Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 1, 2014 at 05:00 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 May 1, 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 to unsettled on June 30. Solar wind speed at SOHO ranged between 303 and 364 km/s.

Solar flux at 20h UTC on 2.8 GHz was 140.5 (increasing 33.5 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 134.3. The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.0). Three hour interval K indices: 31101111 (planetary), 42111432 (Boulder).

The background x-ray flux is at the class C1 level.

At the time of counting spots (see image time), spots were observed in 13 active regions using 2K resolution (SN: 288) and 9 active regions using 1K resolution (SN: 158) SDO images on the visible solar disk.

Region 12096 [N10W23] decayed slowly and quietly.
Region 12097 [N12W30] decayed slowly and quietly.
Region 12100 [N10E12] gained a few spots and was mostly quiet.
Region 12102 [N14E46] developed slowly and quietly.
Region 12103 [S12E25] reemerged with penumbra spots.
Region 12104 [S10E53] gained spots and remains a complex and compact region capable of producing a major flare.
Region 12105 [S06E12] decayed slowly and quietly.
Region 12106 [N15E62] developed slowly and produced a few low level C flares.
Region 12107 [S20E62] was mostly unchanged and has a magnetic delta structure in the southwestern penumbra. An M class flare is possible.

Spotted regions not numbered (or interpreted differently) by SWPC:
New region S3597 [N26W05] emerged with a penumbra spot.
New region S3598 [S08E80] rotated into view with a penumbra spot.
New region S3599 [N06E44] was observed with penumbra spots.
New region S3600 [S31W06] emerged with a penumbra spot.

C2+ Flares (GOES):

Magnitude Peak time (UTC) Location AR
C2.5 (LDE) 03:09 N16E81 12106
C3.4 04:19 S11E64 12104
C2.2 07:02 N09E20 12100
C3.4 13:18   12106

Coronal mass ejections (CMEs)

June 28-30: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.

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 poorly defined coronal hole was in an Earth facing position on June 30.

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 1-3.

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
12096 2014.06.21
2014.06.22
2 6 3 N09W36 0020 CSO CAO

 

12097 2014.06.22 1 3 2 N12W30 0020 HSX HRX  
12098 2014.06.23
2014.06.24
      S09W63           plage
12100 2014.06.25
2014.06.27
12 30 15 N09E11 0060 DAI DRI

location: N10E12

S3579 2014.06.26       S10W04           plage
12099 2014.06.26
2014.06.27
      S16W47           plage
12101 2014.06.26
2014.06.27
      S07W60           plage
12103 2014.06.26
2014.06.28
  3   S10E24 0006   BXO   location: S12E25
S3583 2014.06.27       N00E32           plage
12102 2014.06.27
2014.06.28
3 25 10 N12E41 0020 CRO DRI beta-gamma

location: N14E46

area: 0110

12104 2014.06.28 7 39 16 S11E51 0350 DKC DKC beta-gamma-delta

area: 0740

location: S10E53

S3587 2014.06.28       S23W06         plage
12107 2014.06.28
2014.06.29
9 16 7 S20E62 0250 DHI DHC area: 0480
S3590 2014.06.28       S23E49         plage
S3591 2014.06.28       S12E31         plage
S3592 2014.06.28       S11W05           plage
12105 2014.06.28
2014.06.29
6 11 5 S06E11 0010 CAI CRO  
12106 2014.06.29 4 18 8 N15E60 0020 DAI DRI area: 0050
S3595 2014.06.29       N17W40         plage
S3596 2014.06.29       N08W45         plage
S3597 2014.06.30   1   S26W05 0001   AXX    
S3598 2014.06.30   1   S08E80 0002   AXX    
S3599 2014.06.30   4 2 N06E44 0010   BXO    
S3600 2014.06.30   1   S31W06 0001   AXX    
Total spot count: 44 158 68  
Sunspot number: 124 288 158  (total spot count + 10 * number of spotted regions)
Weighted SN: 92 198 108  (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): 74 101 87 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 82.0 (76.9 projected, +0.9) 5.44
2014.02 170.3
(cycle peak)
166.3 102.8 (cycle peak) (76.7 projected, -0.2) 10.70
2014.03 149.9 148.5 92.2 (77.1 projected, +0.4) 4.88
2014.04 143.9 144.8 84.7 (76.2 projected, -0.9) 7.88
2014.05 129.7 132.9 75.2 (73.7 projected, -2.5) 5.75
2014.06 122.0 125.8 71.0 (71.0 projected, -2.7) 6.7
2014.07 (1)   0.0 (2A/2B) / 79.7 (2C) (68.3 projected, -2.7) ()

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.