Evaluation of the Geomagnetic Reference Field Models in North-Western Pacific Region
Fujita, S., Kawamura, M. & Yukutake, T.
Abstract
The GSI (Geographical Survey Institute) model, the MSA (Maritime Safety Agency) model and the IGRF proposed by the Edinburgh resolution of IAGA are compared with data in 1980 at permanent observatories in the north-western Pacific region. As a result, evaluation indicates that the GSI model can be used only in the Japanese main islands (Hokkaido, Honshu, Shikoku and Kyushu) and that the MSA model is acceptable in the Japanese main islands and in its surrounding region. The IGRF in 1980 is acceptable in the whole region but it has discrepancies of about 100 nT - 200 nT for F, H and Z and about 10 minutes for D from observed data in Japanese main islands. Since the difference between IGRF and observation is not more than about 100 nT during 1965-1980 in this region for the geomagnetic total intensity, a magnetic anomaly chart of total force based on the IGRF has accuracy of about 100 nT when the data employed are measured in this term.
