Regional orthogonal models of the geomagnetic field changes over the Far East

Abstract

Two spatial-temporal models of the geomagnetic field secular variations in a time interval from 1970.0 to 1995.0 were constructed for the Far East region using the technique of regional modeling. First model covers a rectangular area, which includes Kamchatka, Sakhalin, the Kuril and Japanese Islands, the Ohotsk and the Japan Seas. Data from Russian, Japanese, and partially, Chinese observatories, and repeat stations were used for its construction. For filling of no data areas (the seas) the global models were used. Second model covers the area of the Japanese Islands and, partially, surrounding seas. Data from the Japanese magnetic observatories and first class repeat station network were utilized for its construction. We used natural orthogonal components method for obtaining temporal and spatial functions of the models. The accuracy of obtained models is much better than that of global models.