79.5 -69.0
glat glon
This file specifies the location of the magnetic North pole.
The values are Latitude and Longitude in decimal degrees.
(i.e. 79.5 Latitude = 79 degrees 30 minutes North)
Negative Longitude means West.
Only the first record of this file is read.
and should contain the values of glat and glon separated by a space.
This file is named "north_pole.txt".
One by this name will exist in the ..\database directory.
The user may put his own in the ..\run directory, 
and it will override the one in the ..\database directory.
Because the location of the magnetic pole has been moving, this will allow some
research to determine if this is important.
If you are not involved in this research, you should not make any changes.

Values of the geomagnetic latitude  must be in the range   60 <= glat <=  90.
Values of the geomagnetic longitude must be in the range -180 <= glon <= 180.
Values outside these ranges will be ignored and the default values will be used.

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Here is some information about the geomagnetic north pole from a correspondence with John Goodman:
    Thanks for the research. It appears that the Geomagnetic Latitude and longitude values were 
the same as published in the USAF Handbook published in 1985... which were the 1960 values really.  
In fact the same values are quoted on page 4-3 of the "Handbook of Geophysics and the Space Environment"
edited by Jursa.
     There has been a migration of the magnetic DIP pole (the north pole pinpointed on maps of the world) 
since that time. Many popular articles have described this. The current position of the magnetic 
north pole is now somewhat further North and westward of the specified VOACAP position you have provided. 
The magnetic DIP=90 position is about 82 degrees N and 250 degrees E (-110 long). VOACAP is 78.5N and -69E. 
On the surface, this doesn't sound very close. However VOACAP uses Geomagnetic Coordinates (CGM I believe). 
The Corrected Geomagnetic Coordinates represents the best fit dipole, and has a different north pole 
that the magnetic DIP pole.
     Recently, I have gone to a web site that computes the position of the magnetic North Pole in CGM 
coordinates and for the current year, it is 81.76 N and -82E. This compares with VOACAP of 78.5 N and -69E. 
The actual distance is not that much away from the VOACAP value (since longitude changes are exaggerated 
near the pole). It is about 300 miles or so I believe.
    My feeling is that if a change were to be made it would be to use 82N and -82E. 
But I'm not so sure it would be that important in the grand scheme of things. 
By the way the south pole has also changed. Does that enter into the VOACAP algorithms? 
(from Greg: VOACAP does not use a location for the magnetic south pole).
    One thing I am checking is the strategy of using the tilted dipole approximation. 
This seems to be standard, and it is closer to the CGM model that is commonly used in studies. 
I'm taking a look at the relationship between the various circumpolar features and the pole. 
Are these gross features more responsive to the location of the "average" CGM model position 
of magnetic north, or to the "transient" position. If it is the latter, then this exercise is 
really academic.
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