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Titel |
Inductive ionospheric solver for magnetospheric MHD simulations |
VerfasserIn |
H. Vanhamäki |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 29, no. 1 ; Nr. 29, no. 1 (2011-01-10), S.97-108 |
Datensatznummer |
250016951
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Publikation (Nr.) |
copernicus.org/angeo-29-97-2011.pdf |
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Zusammenfassung |
We present a new scheme for solving the ionospheric boundary conditions
required in magnetospheric MHD simulations. In contrast to the electrostatic
ionospheric solvers currently in use, the new solver takes ionospheric
induction into account by solving Faraday's law simultaneously with Ohm's law
and current continuity. From the viewpoint of an MHD simulation, the new
inductive solver is similar to the electrostatic solvers, as the same input
data is used (field-aligned current [FAC] and ionospheric conductances) and
similar output is produced (ionospheric electric field). The inductive solver
is tested using realistic, databased models of an omega-band and westward
traveling surge. Although the tests were performed with local models and MHD
simulations require a global ionospheric solution, we may nevertheless
conclude that the new solution scheme is feasible also in practice. In the
test cases the difference between static and electrodynamic solutions is up
to ~10 V km−1 in certain locations, or up to 20-40% of the total electric
field. This is in agreement with previous estimates. It should also be noted
that if FAC is replaced by the ground magnetic field (or ionospheric
equivalent current) in the input data set, exactly the same formalism can be
used to construct an inductive version of the KRM method originally developed
by Kamide et al. (1981). |
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