HFguy wrote:
Lisa Simpson wrote:

Having no long term experience in SWL personally, would those with a
couple
cycle's worth please share their experiences? What can we expect for the
next ~11 years?


That's a tall order Lisa, but in general as the next sunspot cycle
begins, the 'solar flux' (energy measured at 2800-Mhz or 10.7-cm
wavelength) will gradually increase over a period of several years. At
the minimum of the cycle such as now, the flux is averaging in the 70-80
range. The flux has dropped into the 60's in some past cycles. At solar
maximum the flux can reach 300. This causes the ionosphere to become
more energized and able to support the propagation of higher frequencies
in the day and well after sunset too. The 17-m and 19-m bands can be
active all night during solar maximum, whereas now they drop out shortly
after sunset because the ionosphere isn't receiving enough energy during
the day to keep it active at night. The ionosphere is a huge cloud of
electrically charged ions (charged atoms) which surrounds the earth
above the lower atmosphere. The sun supplys the energy during the day
which keeps the ions separate from electrons. This condition is
necessary to support the propagation (refraction) of radio energy. At
night the ions and electrons slowly recombine into neutral atoms which
do not support radio propagation. Of course the sun is always shining on
half the earth so this process is going on all the time somewhere in the
ionosphere.
The down side to a more active sun during the maximum of the cycle is an
increase in solar storms which can emit high energy particles and
radiation. This can wreck havoc with the ionosphere, making it
effectively useless for radio propagation for hours or even days.
Sunspots have been seen by man for at least a thousand years, probably
much longer. Scientists have been studying the sunspot cycle since the
middle of the 18th century. We are currently experiencing a quite sun at
the end of cycle-23 which began in May-1996. The first signs of cycle-24
will be the appearance of sunspots at low latitudes near the sun's
equator. These will gradually expand towards the higher latitudes as the
cycle progresses. The sunspot cycle is driven by the dynamics of the
sun's magnetic properties. You might enjoy reading more about it at the
following website.

http://www.windows.ucar.edu/tour/lin.../sunspots.html
http://www.windows.ucar.edu/tour/lin...pot_cycle.html


Here's an interesting story on the latest sunspot cycle theory.

http://www.msnbc.msn.com/id/11701699/