Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 24, 2014 at 04:20 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update June 1, 2014)] [Cycle 24 progress (last update June 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update June 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update June 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 23. Solar wind speed at SOHO ranged between 281 and 394 km/s. A weak solar wind shock was observed at 22:00 UTC at SOHO, the low solar wind speed indicates that this may have been the arrival of the June 19 CME.

Solar flux at 20h UTC on 2.8 GHz was 92.6 (decreasing 13.3 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 136.9. The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.9). Three hour interval K indices: 10000013 (planetary), 00012323 (Boulder).

The background x-ray flux is at the class B1 level.

At the time of counting spots (see image time), spots were observed in 6 active regions using 2K resolution (SN: 83) and 5 active regions using 1K resolution (SN: 62) SDO images on the visible solar disk.

Region 12093 [S06W36] decayed quickly and lost the trailing spots.
Region 12094 [S17W22] decayed further and was quiet.
Region 12096 [N09E57] was quiet and stable.
Region 12097 [N13E64] was quiet and stable.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3559 [S10W27] decayed slowly and quietly.
New region S3570 [S07E32] emerged with penumbra spots.

C2+ Flares (GOES):

Magnitude Peak time (UTC) Location AR
       

Coronal mass ejections (CMEs)

June 21-23: 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 trans equatorial coronal hole (CH623) could rotate into an Earth facing position on June 23-24.

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 to unsettled on June 24 due to CME effects and quiet on June 25. Quiet to unsettled conditions are possible on June 26-27 due to effects from CH623.

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
12090 2014.06.10
2014.06.11
1     N25W90 0030 HSX     rotated out of view
12092 2014.06.11
2014.06.12
      S19W88        

plage

12093 2014.06.15
2014.06.16
8 1   S09W32 0020 CRO AXX area: 0001

location: S06W36

12094 2014.06.15
2014.06.16
3 1 1 S18W23 0010 AXX AXX  
S3547 2014.06.16       N16W58           plage
S3555 2014.06.18       N03W49           plage
S3556 2014.06.19       N11W42           plage
S3558 2014.06.20       N15W23           plage
S3559 2014.06.21   10 5 S10W27 0015   BXO  
S3561 2014.06.21       S20W50           plage
12096 2014.06.21
2014.06.22
1 2 2 N08E56 0080 HSX HAX area: 0130
S3564 2014.06.21       S19W40           plage
12097 2014.06.22 1 3 1 N13E64 0030 HAX HAX area: 0070
S3567 2014.06.22       S01E04         plage
S3568 2014.06.22       N13W16         plage
S3569 2014.06.22       N15W42         plage
S3570 2014.06.23   6 3 S07E32 0020   BXO
Total spot count: 14 23 12  
Sunspot number: 64 83 62  (total spot count + 10 * number of spotted regions)
Weighted SN: 32 33 22  (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): 38 29 34 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 (75.8 projected, +0.4) 4.68
2014.01 157.4 152.4 82.0 (76.4 projected, +0.6) 5.44
2014.02 170.3
(cycle peak)
166.3 102.8 (cycle peak) (76.2 projected, -0.2) 10.70
2014.03 149.9 148.5 92.2 (76.6 projected, +0.4) 4.88
2014.04 143.9 144.8 84.7 (75.8 projected, -0.8) 7.88
2014.05 129.7 132.9 75.2 (73.2 projected, -2.6) 5.75
2014.06 124.0 (1)   90.2 (2A) / 112.8 (2B) / 76.4 (2C) (70.5 projected, -2.7) (7.1)

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.