I.M. Demina, A.A. Petrova

The article presents a research in accuracy of forecast of secular variation of the Earth’s main magnetic field calculated using generally accepted international model of a normal field. An inaccuracy of the forecast for the Russian territory is structured and its gradient covers the territories of Siberia and the Far East. Over the period 2000-2005 the inaccuracy comprised -300 nT. The authors obtained estimations of discrepancies which may accompany the generalized mapping of an anomalous magnetic field using just the secular variation forecast or trend. We have compared the forecast of the main field secular variation for the period up to 2010 and its real variations recorded by magnetic observatories.
The five year forecast does not show the current variations in the history of the secular variation. It is necessary to create and support a regional model of the main magnetic field based on a network of magnetic observatories and repeat stations. It seems that the most advanced methods should combine data from global satellite survey and a network of permanent observatories.

Keywords: variations, forecast, anomalous magnetic field, repeat station network.