[ADXA] Drift of the Magnetic North Pole - W3LPL

[w5zn at w5zn.org]

Thanks to Bernie, W3UR and The Daily DX for granting ADXA permission to 
reprint Frank, W3LPL's writing below pertaining to the drift of the 
magnetic north pole that appeared in today's The Daily DX.

Thanks Bernie!

73 Joel W5ZN
______________________________________________________________________

Confusion among hams about the increasingly rapid drift of the
magnetic north pole
By W3LPL, Frank Donovan
______________________________________________________________________

There's considerable confusion and misinformation in the amateur radio
community caused by misinterpretation of press reports about the
surprisingly rapid rate of northward drift of the Earth's magnetic
north pole over roughly the last 35 years.

Contributing to the confusion are two broadly defined magnetic north
poles:
    - the fairly rapidly drifting dip north pole (often called
the magnetic pole), and
    - the relatively slowly drifting geomagnetic north pole

The dip north pole being discussed in current news reporting is
drifting northward ten times more rapidly than the more lethargic
geomagnetic north pole which has much greater significance to DXers
and contesters.

www.scientificamerican.com/article/the-earth-has-more-than-one-north-pole

The slowly drifting geomagnetic north pole has much greater
significance to DXers and contesters because the northern auroral oval
- which greatly affects HF propagation over the north Atlantic and
north Pacific
Oceans -- is closely centered on the geomagnetic north pole and not on
the dip north pole.  The geomagnetic north pole has been drifting
generally northward only about three miles per year.

The geomagnetic north pole's location is defined by global models of
the Earth's magnetic field, its location cannot be determined by
direct measurement.  Its currently located on Ellesmere Island about
165 miles southwest of Alert, Nunavut the northernmost permanently
inhabited place on Earth. Its drifting much more slowly than the dip
north pole, it has drifted roughly northward only about 75 miles over
the last twenty years.

The much more rapidly drifting dip north pole is defined to be the
location in the northern hemisphere where the geomagnetic field is
exactly vertical as determined experimentally by magnetic surveys on
land, ships and spacecraft. Its location is currently near the center
of the Arctic Ocean about 250 miles southeast of the geographic north
pole roughly halfway between Nunavut and Eastern Siberia. The location
of the dip north pole is important to navigation but of relatively
little importance to space-based phenomenon such as HF ionospheric
propagation.