The study of change in the location of the geomagnetic north pole for the epoch (1900-2005) by using spherical harmonic coefficient.

الملخص

The study of change in the location of the geomagnetic north pole for the epoch (1900-2005) by using spherical harmonic coefficient.

In this paper we study the nature of the location change of geomagnetic north pole (GMNP) for epoch (1900-2005). Using the spherical harmonic coefficient defining the International Geomagnetic Reference Field Model (IGRF) for the (22) epochs (1900-2005), the coordinates of the (GMNP) (longitude and latitude) were computed. Also, I study the secular variation of total intensity () and declination (D) (the angle between the horizontal component of the geomagnetic field and true geographic north ) at the geomagnetic north pole location (lat 79.73^°N, long 71.82^°W , year 2005), we found that the rate of change of field intensity (F) is roughly (0.04-0.06% per year).The declination change from (14^o west ) to (25^o east ).