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| Titel:
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Geomagnetic core field models in the satellite era |
| Type:
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Book chapterBook chapter |
| Person(er):
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Forfatter:
Lesur, Vincent
GFZ German Research Centre for Geosciences
Technical University of Denmark
Email:
Forfatter:
Thomson, Alan W. P.
Technical University of Denmark
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| Uddrag:
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After a brief review of the theoretical basis
and difficulties that modelers are facing, we present
three recent models of the geomagnetic field originating
in the Earth’s core. All three modeling approaches
are using recent observatory and near-Earth orbiting
survey satellite data. In each case the specific aims and
techniques used by the modelers are described together
with a presentation of the main results achieved. The
three different modeling approaches are giving similar
results. For a snap shot of the core magnetic field
at a given epoch and observed at the Earth’s surface,
the differences between models are generally small.
They do not exceed 16 nT which gives an idea of the
accuracy of the models. Secular variation models are
robustly resolved up to spherical harmonic degree 13,
but only on time scale as large as 10 years. On time
scale of a year, secular variation models are resolved
only up to degree 8 or 9. For higher time derivatives
of core field models, only the very first degrees are
robustly derived. |
| Publiceret:
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part of: Geomagnetic Observations and Models (ISBN: 978-9048198573), pages: 277-294, 2011, Springer Science+Business Media B.V., |
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