Unless you've studied geomagnetic physics you probably never learned
-- or even heard -- that the Earth has three north poles. The BBC
article -- referenced by the first email in this chain -- describes the three
types of poles very well, but not at all how they relate to space physics.
https://www.bbc.com/news/science-environment-52550973
- the geographic north pole is where the Earth's rotation axis intersects
the Earth's surface in the northern hemisphere.
- the magnetic north pole is important to navigation systems and is the
primary subject of the BBC article. It is the location in the northern
hemisphere where the Earth's magnetic field lines are measured to
be exactly perpendicular to the Earth's surface.
- the geomagnetic north pole is important to HF propagation
and many other aspects of the Earth's space environment
The geographic north pole affects HF propagation because the
Earth's tilt determines the our daylight/darkness cycles throughout
the seasons of the year.
The magnetic north pole is a pole most of us know about and
the one being discussed in this chain of emails. I ts position has
been drifting about 50-60 km per year for about the last forty
years. Bob KQ2M asked about the significance of this fairly
rapid drift: It has no significance to HF propagation.
The geomagnetic n orth pole 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 HF propagation
because it describes the position of the geomagnetic field in the Earth's
space environment including -- very importantly -- its ionosphere.
The geomagnetic field very profoundly affects HF propagation.
The geomagnetic north pole drifts only about one km. per year.
https://ichef.bbci.co.uk/news/624/cpsprodpb/13DC2/production/_112164318_new-nc.png
As an aside, while the magnetic n orth pole is drifting fairly rapidly,
the magnetic south pole is drifting very little.
73
Frank
W3LPL
----- Original Message -----
From: "Tonno Vahk" <tonno.vahk@gmail.com>
To: "Bob Shohet, KQ2M" <kq2m@kq2m.com>
Cc: hhamwv@gmail.com, "cq-contest" <cq-contest@contesting.com>
Sent: Wednesday, May 6, 2020 7:17:19 PM
Subject: Re: [CQ-Contest] Russian Beats Out Canada for Magnetic North ... For
Now
for me at KO38CS the declination is 9.43 degrees now and I have used 10 degrees
for a while.
Though 20 years ago the declination was 6.57 degrees and 10 years ago 7.75
degrees. So it is climbing:)
100 years ago the declination was zero and we had no trouble of adding the
coefficient to the compass reading:)
73
ES5TV
On 6. May 2020, at 20:10, Bob Shohet, KQ2M <kq2m@kq2m.com> wrote:
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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