README for the Leeds Directory of Magnetic Declination Data and Software
7 September 2006, S. Lubker

The declination data file (gufm1) and Fortran program (calc_di_vs_time.f) were
received in 2005 from KNMI (Frits Koek) in a zip file.  The data and software
are described in the following message excerpt:

=>Date: Thu, 21 Apr 2005 13:56:26 +0200
=>From: "Frits B. Koek" <koek@knmi.nl>
=>To: "Scott Woodruff" <Scott.D.Woodruff@noaa.gov>
=>Subject: Re: US Maury and Met Journals Collections
. . .
=>1. Referring to the first question about the magnetic variation, I
=>attached a fortran program and a datafile that I received from Leeds
=>University (UK). The program calculates the magnetic variation at any
=>position and year between 1590-1997, which I think suits your needs.
. . . 

-r--r--r--   1 sjl      coads     299882 Aug 31 13:36 Leeds.zip
-rw-r--r--   1 sjl      coads      16390 May 13  2003 calc_di_vs_time.f
-rw-r--r--   1 sjl      coads     751886 May 13  2003 gufm1

Andrew Jackson, Art R. T. Jonkers, Matthew R. Walker, Four centuries of
geomagnetic secular variation from historical records, Philosophical
Transactions of the Royal Society A: Mathematical, Physical and Engineering
Sciences , Volume 358, Issue 1768, 15 Mar 2000, Pages 957 - 990, DOI
10.1098/rsta.2000.0569, URL http://dx.doi.org/10.1098/rsta.2000.0569