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A model of geomagnetic secular variation for 1980-1983

Physics of the Earth and Planetary Interiors

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,
DOI: 10.1016/0031-9201(87)90155-5

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Abstract

We developed an updated model of the secular variation of the main geomagnetic field during 1980 through 1983 based on annual mean values for that interval from 148 worldwide magnetic observatories. The model consists of a series of 80 spherical harmonics, up to and including those of degree and order 8. We used it to form a proposal for the 1985 revision of the International Geomagnetic Reference Field (IGRF). Comparison of the new model, whose mean epoch is approximately 1982.0, with the Provisional Geomagnetic Reference Field for 1975-1980 (PGRF 1975), indicates that the moment of the centered-dipole part of the geomagnetic field is now decreasing faster than it was 5 years ago. The rate (in field units) indicated by PGRF 1975 was about -25 nT a-1, while for the new model it is -28 nT a-1. ?? 1987.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
A model of geomagnetic secular variation for 1980-1983
Series title:
Physics of the Earth and Planetary Interiors
DOI:
10.1016/0031-9201(87)90155-5
Volume
48
Issue:
3-4
Year Published:
1987
Language:
English
Publisher:
Elsevier
Publisher location:
Amsterdam, Netherlands
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Physics of the Earth and Planetary Interiors
First page:
324
Last page:
329
Number of Pages:
6