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| Titel |
Computations of wind-driven ocean-induced magnetic fields |
| VerfasserIn |
Libor Šachl, David Einspigel, Zdeněk Martinec |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250128967
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| Publikation (Nr.) |
 EGU/EGU2016-9021.pdf |
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| Zusammenfassung |
| We present the results of computations of the secondary magnetic field induced by ocean
motions. Ocean velocities are computed using the baroclinic ocean model LSOMG. The
velocities are then used to determine the Lorentz force which is plugged into the
magnetic induction code TLAM as a principal forcing. The TLAM is a 2D magnetic
induction code based on the thin-shell approximation (Vivier et al., 2004; Tyler et
al., 1997). In this approximation, the equation of magnetic induction simplifies
significantly, time derivatives of main and induced magnetic fields are neglected as
well as the self-induction term. The price for simplification of governing equations
is the limited applicability of the resulting system. It is only suitable for slowly
evolving processes. In order to meet the condition, we restrict ourselves to the wind
(buoyancy) driven ocean circulation, although the LSOMG model is able to model
both tidally- and wind-driven circulations. We assess the accuracy of thin-shell
approximation in our setup by comparing the results with the Swarm satellite magnetic
data.
References
Tyler, R. H., Mysak, L. A., and Oberhuber, J. M, 1997. Electromagnetic fields
generated by a three dimensional global ocean circulation. J. Geophys. Res., 102,
5531–5551.
Vivier, F., Meier-Reimer, E., and Tyler, R. H., 2004. Simulations of magnetic
fields generated by the Antarctic Circumpolar Current at satellite altitude: Can
geomagnetic measurements be used to monitor the flow? Geophys. Res. Lett., 31, L10306,
doi:10.1029/2004GL019804. |
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