The geomagnetic jerk of 1969 and the DGRFs

D. Thompson; J.C. Cain

doi:10.1016/0031-9201(87)90163-4

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The geomagnetic jerk of 1969 and the DGRFs

D. Thompson·J.C. Cain

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Abstract

Cubic spline fits to the DGRF/IGRF series indicate agreement with other analyses showing the 1969-1970 magnetic jerk in the h ??12 and g ??02 secular change coefficients, and agreement that the h ??11 term showed no sharp change. The variation of the g ??01 term is out of phase with other analyses indicating a likely error in its representation in the 1965-1975 interval. We recommend that future derivations of the 'definitive' geomagnetic reference models take into consideration the times of impulses or jerks so as to not be bound to a standard 5 year interval, and otherwise to make more considered analyses before adopting sets of coefficients. ?? 1987.

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D. Thompson, J.C. Cain. 1987. The geomagnetic jerk of 1969 and the DGRFs. https://doi.org/10.1016/0031-9201(87)90163-4

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