Hi Ken,
BBC's article this week " Scientists explain magnetic pole's wanderings"
has attracted the interest of many radio amateurs interested in ionospheric
propagation.
www.bbc.com/news/science-environment-52550973
Unless you've studied geomagnetic physics you probably never learned
-- or even heard -- that the Earth has three north poles. The BBC
article describes the poles very well, but does not address the
relationship between the poles and ionospheric propagation.
The geographic north pole is where the Earth's rotation axis intersects
the Earth's surface in the northern hemisphere. It affects ionospheric
propagation because the orientation of Earth's tilted axis to the Sun varies
with the seasons and determines our daylight/darkness cycles throughout
the year.
While the magnetic north pole -- the focus of the BBC article -- is important
to navigation systems, it has no significance to ionospheric propagation.
Most of us learned about the magnetic north pole when we learned how
to use a compass, it is located in the northern hemisphere where the Earth's
magnetic field lines are measured to be exactly perpendicular to the Earth's
surface. I ts position has been drifting about 50-60 km per year for about the
last forty years.
The geomagnetic north pole -- only briefly described in the BBC article --
is very important to ionospheric propagation and many other aspects of
the Earth's space environment. It is the intersection of the Earth's surface
in the northern hemisphere and the axis of a bar magnet hypothetically
placed at the center the Earth. It is very significant for ionospheric
propagation because it determines the position of the geomagnetic field
in the Earth's space environment including -- very importantly --
its ionosphere. The geomagnetic field very profoundly affects ionospheric
propagation. The geomagnetic north pole drifts only about one km. per year,
a tiny fraction of the movement of the magnetic north pole described in the
BBC article.
https://ichef.bbci.co.uk/news/624/cpsprodpb/13DC2/production/_112164318_new-nc.png
As an aside, while the magnetic north pole is drifting fairly rapidly,
the magnetic south pole is drifting very little at all.
73
Frank
W3LPL
----- Original Message -----
From: "ktfrog007--- via CQ-Contest" <cq-contest@contesting.com>
To: kq2m@kq2m.com, cq-contest@contesting.com, hhamwv@gmail.com
Sent: Thursday, May 7, 2020 12:07:35 PM
Subject: Re: [CQ-Contest] Russian Beats Out Canada for Magnetic North ... For
Now
Another question: Has the magnetic polar drift affected propagation over the
decades?
I don't have any data except my own unreliable memory and old logs, but my
feeling is that back in the 1960-1990 time frame long haul DX propagation was
better than now, at least for my operations from Indiana, Colorado and
Massachusetts.
It's interesting that the magnetic pole moved less in that time frame and then
rapidly accelerated up to the present.
It seems to me that DXing was better back then, but it's difficult to separate
that from the declining sunspot cycles and the changes in ham demographics.
73,
Ken, AB1J
-----Original Message-----
From: Bob Shohet, KQ2M <kq2m@kq2m.com>
To: cq-contest <cq-contest@contesting.com>; hhamwv@gmail.com
Sent: Wed, May 6, 2020 5:10 pm
Subject: Re: [CQ-Contest] Russian Beats Out Canada for Magnetic North ... For
Now
Hi Dave,
Thanks for posting that interesting article.
What effect, if any, does this have on beam headings through the Northern
regions – like UA0, UA3, JA?
Does it change them at all? If so, how and by what amount?
Tnx & 73
Bob, KQ2M
From: David Siddall
Sent: Wednesday, May 6, 2020 11:22 AM
To: cq-contest
Subject: [CQ-Contest] Russian Beats Out Canada for Magnetic North ... For Now
Good thing HF antennas generally have relatively wide beam width if you use
a compass to orient without correcting for deviation.
This also has a subtle effect on propagation paths through the polar areas,
depending upon your location.
https://www.bbc.com/news/science-environment-52550973
73, Dave K3ZJ
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