Thursday, May 2, 2013

The 2012-2013 Fall/Winter 10-Meter "F2" Season

Hi everyone,
Sorry, I am weeks late with the recap.

How The Season Started:
    During the early parts of the fall of 2011 we saw a rapid acceleration of solar activity. In November 2011, the first reports of 6-Meter F2 propagation occurred. Things looked up.  By January 2012, it stopped and started a slow and steady decline.
    Throughout the summer there were minor peaks of solar activity, but it never increased overall.  The decline sadly continued throughout the fall and winter of 2012-13.

Comparing Solar Flux from the 26 weeks of the fall/winter seasons, only 3 weeks of 2012-13 were higher than 2011-12.
Sunspot numbers were better for about 9 weeks, but failed to produce higher solar flux numbers.
Other than the third week of the season, little storming of the Sun occurred. When storms occurred, there was not much of a rise in solar flux.

For 2012-13 on average, Solar Flux was 16 points lower, sunspot numbers 18 lower and the A-Index 1 point lower than the 2011-12 counterpart.

F2 MUF is based on the average Solar Flux for the week measured to a designated location optimum for single hop F2 propagation (1425 miles).  Average daily MUF was 17.2 MHz this season, a decline of 1.4 MHZ from the previous season. At the end of 2012, the difference was 2.2 MHz.

The lower MUF had a drastic affect on the number of available hours of 10-Meter propagation. For 13 weeks of the 26 week season hardly any opportunity of 10-Meter F2 existed.

The Results:
For 2012-13, captures declined 60%.  The difference percentage was set by the winter solstice. Captures during 2012-13 were 9,958. In 2011-12 there were 24,772.

Only two weeks of the season did 2012-13 exceed the same week of 2011-12.  There were only two weeks of the season that could be considered highly active (1,000+ captures). Many weeks little to no activity.

The chart above represents sunrise to sunset, and back to sunrise.
As noted, captures in 2011-12 were best in the morning hours ( East coast and Europe F2).  This season all hours were lower and favored afternoon periods (mostly Trans-Equatorial) that was less dependent on a high solar flux.
2012-13 Global Coverage
Despite the lower solar numbers coverage was not as bad. 544 grid squares, 80 DXCC entities were logged.

2011-12 Global Coverage
652 grid squares, 80 DXCC entities were logged last year.
A total of 792 grids squares and 94 DXCC entities have been logged in 2 seasons.

Hourly Breakdown
The hourly figures clearly reflect the lack of solar activity.  When solar numbers are higher the morning hours are much higher than afternoon. Propagation to ham populations from this QTH results in better morning activity.  This includes the east coast of the U.S. and Canada, as well as Europe.  This year those numbers of captures were very low.

This season, afternoon captures were more influential in the capture totals. Changes in 1,750-3,500 and 3,500-4,750 had the most influence.

Winter Es:

High solar flux is a definite help and strongly influences Winter Es. This year was much more normal in volume and trends and showed little affects from the sun. 


This all appears to be a bit doom and gloom, but a few physicists believe that we will see a dual peak in this cycle.  The past two cycles have and with the mistiming of the crossing of the solar poles that should occur. There is always next year.

Art Jackson 

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