Solar Terrestrial Activity Report

Activity chart

Last major update issued on June 14, 2013 at 04:50 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, 2013)] [Cycle 24 progress (last update June 1, 2013) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update June 1, 2013)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update June 1, 2013)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update June 6, 2013)]

[POES auroral activity level since October 2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated May 12, 2013]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet on June 13. Solar wind speed at SOHO ranged between 334 and 443 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 98.9 (decreasing 37.5 over the last solar rotation). The Potsdam WDC planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 2.6). Three hour interval K indices: 21000101 (planetary), 11011221 (Boulder).

The background x-ray flux was at the class B3 level.

At midnight UTC the visible solar disk had 9 spotted active regions (in 2K resolution SDO images).

Region 11768 [S12W32] developed quickly and has become a compact region with minor polarity intermixing. C flares are certainly likely, and further development will make M flares possible.
New region 11769 [S23E62] rotated into view on June 12 and was numbered the next day by SWPC.
New region 11770 [S14E69] rotated into view on June 12 and got its NOAA number the following day.

Spotted regions not numbered by SWPC:
S2467 [S13W41] reemerged with a penumbra spot.
S2468 [S32E08] reemerged with penumbra spots.
S2469 [N13W09] was quiet and stable.
New region S2476 [S20E69] rotated into view with several spots.
New region S2477 [S12E79] rotated into view with one spot.
New region S2478 [N07E20] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

June 11-13: 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

No obvious 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 high and upper middle latitudes is poor to fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on June 14-16.

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: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% 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 STAR SDO SWPC STAR Current Previous
2K 1K
S2463 2013.06.06       N06W48         plage
S2464 2013.06.07       N25W53           plage
11767 2013.06.07
2013.06.09
      S17W14          
S2467 2013.06.07   1   S13W41 0002   AXX   plage
S2468 2013.06.08   2   S32E08 0004   BXO    
S2469 2013.06.09   10 1 N13W09 0017   BXO images/AR_S2469_20130613_2345.jpg images/AR_S2469_20130612_2345.jpg  
S2470 2013.06.09       S24W34           plage
11768 2013.06.11
2013.06.12
12 25 11 S11W32 0090 DAI DAC beta-gamma

area: 0320

S2473 2013.06.11       S13W28           plage
11770 2013.06.12
2013.06.13
1 1 1 S13E67 0030 HSX HSX area: 0090
11769 2013.06.12
2013.06.13
2 4 3 S23E61 0010 BXO DRO area: 0035
S2476 2013.06.13   6 1 S20E69 0015   BXO    
S2477 2013.06.13   1 1 S12E79 0015   HRX    
S2478 2013.06.13   1   N07E20 0003   AXX    
Total spot count: 15 51 18  
Sunspot number: 45 141 78  (total spot count + 10 * number of spotted regions)
Weighted SN: 25 67 34  (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): 27 49 43 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for STAR SDO 2K, k = 0.55 for STAR SDO 1K

Monthly solar cycle data

Month Average measured solar flux International sunspot number (SIDC) Smoothed sunspot number Average ap
(3)
2011.11 153.5 (cycle peak) 96.7 (cycle peak) 61.1 (+1.2) 5.55
2012.02 106.5 32.9 66.9 (+1.4)
possible cycle 24 max
8.81
2012.03 114.7 64.3 66.8 (-0.1) 16.08
2012.04 113.0 55.2 64.6 (-2.2) 10.10
2012.05 121.5 69.0 61.7 (-2.9) 7.06
2012.06 119.6 64.5 58.9 (-2.8) 10.08
2012.07 133.9 66.5 57.7 (-1.2) 13.90
2012.08 115.4 63.0 58.1 (+0.4) 7.96
2012.09 122.9 61.4 58.1 (-0.0) 8.07
2012.10 123.3 53.3 58.6 (+0.5) 9.97
2012.11 121.3 61.8 59.7 (+1.1) 7.08
2012.12 108.6 40.8 (59.5 projected, -0.2) 3.44
2013.01 127.1 62.9 (59.1 projected, -0.4) 4.69
2013.02 104.3 38.0 (59.3 projected, +0.2) 6.11
2013.03 111.3 57.9 (58.9 projected, -0.4) 10.56
2013.04 124.8 72.4 (58.6 projected, -0.3) 5.40
2013.05 131.4 78.7 (58.7 projected, +0.1) 9.73
2013.06 103.1 (1) 23.2 (2A) / 53.6 (2B) / 55.0 (2C) (59.0 projected, +0.3) (12.81)

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 SIDC 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 Potsdam WDC ap indices.

This report has been prepared by Jan Alvestad. It is based on 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.