Last major update issued on August 12, 2014 at 04:40 UTC.
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[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]
The geomagnetic field was quiet to unsettled on August 11. Solar wind speed at SOHO ranged between 373 and 462 km/s.
Solar flux at 20h UTC on 2.8 GHz was 105 (increasing 4.2 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 132.1. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.1). Three hour interval K indices: 11111213 (planetary), 21112313 (Boulder).
The background x-ray flux is at the class B2 level.
At the time of counting spots (see image time), spots were observed in 9 active regions using 2K resolution (SN: 152) and 6 active regions using 1K resolution (SN: 85) SDO images on the visible solar disk.
Region 12134 [N11W51] decayed further and was quiet.
Region 12135 [N14W07] decayed slowly producing a single low level C flare.
Region 12137 [S18W36] was quiet and stable.
New region 12138 [N13W69] emerged quickly during the first half of the day.
New region 12139 [N17E71] rotated into view on August 10 with SWPC numbering the region the next day.
Spotted regions not numbered (or interpreted differently) by SWPC:
S3720 [N13W37] developed slowly and quietly.
S3723 [S23W03] was quiet and stable.
New region S3727 [N06E19] emerged with a penumbra spot.
New region S3728 [S17E20] was observed with penumbra spots.
|Magnitude||Peak time (UTC)||Location||AR|
August 9-11: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
[Coronal hole history (since October
[Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago]
A small trans equatorial coronal hole (CH631) was in an Earth facing position on August 9-10.
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.
The geomagnetic field is expected to be mostly quiet on August 12-14. There is a chance of weak effects from CH631 on August 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
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.
(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
|Spot count||Location at midnight||Area||Classification||SDO / HMI 4K continuum
image with magnetic polarity overlay
rotated out of view
it's uncertain what SWPC has observed. No spots observed in SDO images during the day at the given location. Maybe a duplicate of AR 12138 with a wrong location
|Total spot count:||22||62||25|
|Sunspot number:||82||152||85||(total spot count + 10 * number of spotted regions)|
|Weighted SN:||47||83||46||(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):||49||53||47||k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for MSN 2K, k = 0.55 for MSN 1K (MSN=Magnetic Sunspot Number)|
|Month||Average solar flux||International sunspot number
|Smoothed sunspot number||Average ap
|166.3||102.3 (cycle peak)||(78.1 projected, +0.8)||10.70|
|2014.03||149.9||148.5||91.9||(79.0 projected, +0.9)||4.88|
|2014.04||143.9||144.8||84.7||(78.1 projected, -0.9)||7.88|
|2014.05||129.7||132.9||75.2||(75.6 projected, -2.5)||5.75|
|2014.06||122.0||125.8||71.0||(72.9 projected, -2.7)||6.72|
|2014.07||137.4||141.8||72.5||(69.9 projected, -3.0)||4.5|
|2014.08||134.2 (1)||43.0 (2A) / 121.3 (2B) / 64.7 (2C)||(66.5 projected, -3.4)||(6.7)|
1) Running average based on the daily 20:00 UTC observed solar flux value at
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.