On Thu, 15 Mar 2007 12:26:08 +0100, JeroenK wrote in
:

Larry Dighera schreef:

So what sort of impact on radio propagation/reception should one
expect a solar hole to impose?

There are no holes in the sun, there are in the corona though. The
correct term is Coronal Hole.


You are correct. Thank you for calling my faux pas to my attention.

My knowledge on propagation needs more deepening (although I have great
interest in Aurora, hence my knowledge on these happenings). Although I
have a base knowledge I hope someone else will chime in who has more
knowledge to ensure I wont feed you nonsense

Does a solar hole result in only increasing the velocity of the solar
wind without the massive increase in particle count that occurs during
a CME event?

A CME is a massive flare with lots of particles released in sudden
events, CHs are more of a steady stream of particles that is however
lots lower in number of particles then a CME.

This is debatable, but CH's should increase proper propagation, and CMEs
can cause storms and as such actually stop propagation.

But again, I hope someone with proper knowledge of spaceweather will
chime in.

Thank you for sharing your knowledge.

It would seem from personal observation, that currently, during a CH
event, the Maximum Useable Frequency (MUF) is considerably lower than
normal, but that may be due solely to the Solar Minimum* we are
currently experiencing.




* http://en.wikipedia.org/wiki/Solar_minimum


(Interesting predictions:
http://science.nasa.gov/headlines/y2..._longrange.htm
Long Range Solar Forecast
05.10.2006
Solar Cycle 25, peaking around 2022, could be one of the weakest
in centuries.
...
A team led by physicist Mausumi Dikpata of NCAR has predicted that
Cycle 24, peaking in 2011 or 2012, will be intense.
http://www.ucar.edu/news/releases/2006/sunspot.shtml
http://science.nasa.gov/headlines/y2...ormwarning.htm
"The next sunspot cycle will be 30% to 50% stronger than the
previous one," she says. If correct, the years ahead could produce
a burst of solar activity second only to the historic Solar Max of
1958.)