Shift of Magnetic Pole may change
Radio Propagation
The BBC news item at http://news.bbc.co.uk/1/hi/sci/tech/4520982.stm
is worth reading. They report that the earth's magnetic North Pole
could shift from Alaska to Siberia in as little as 50 years.
As well as steadily drifting over the centuries the earths magnetic
poles have in recent geological times completely flipped with the
North Pole being in Antarctica.
A 2002 New Scientist article http://www.newscientist.com/article.ns?id=dn2152
pointed out that the earths magnetic dipole occasionally disappears
altogether, leaving a much more complicated field with many poles
all over the planet. When the dipole comes back into force, the
north and south poles can swap places. All of which indicates that
the earth’s magnetic field is perhaps as unstable as the climate.
What effect will this have on Radio Propagation? Well it’s
clear the regions for best VHF Auroral propagation will move as
the magnetic North Pole drifts. I am not clear how this would affect
the United Kingdom but some people speculate that the drift of the
magnetic pole into Siberia would increase visible auroras in parts
of Europe.
If the earth’s magnetic field collapsed during a flip-over
we may see increases in incoming cosmic rays and particles in the
solar wind, which would normally be deflected by the earth's magnetic
field. This may well affect the ionosphere. Could we see increased
ionospheric propagation at 50 and 70 MHz? Who knows? One thing’s
for certain - we live in interesting times.
73 Trevor M5AKA
Some useful websites:
When the Poles Flip
http://www.gi.alaska.edu/ScienceForum/ASF7/759.html
University of Alaska Geophysical Institute
– Aurora Forecast
http://www.gi.alaska.edu/cgi-bin/predict.cgi
Real Time Propagation Maps
http://www.vhfdx.net/mufmap.html
HF Radio Propagation
http://hfradio.org/propagation.html
Solar Terrestrial Dispatch
http://www.spacew.com/
Space Weather
http://www.spaceweather.com/
Australian Space Weather Agency – HF Systems
http://www.ips.gov.au/Main.php?CatID=6
Solar Terrestrial Activity Report
http://www.dxlc.com/solar/
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