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Titel |
Ionospheric control of the magnetosphere: conductance |
VerfasserIn |
A. J. Ridley, T. I. Gombosi, D. L. DeZeeuw |
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 ; 22, no. 2 ; Nr. 22, no. 2 (2004-01-01), S.567-584 |
Datensatznummer |
250014783
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Publikation (Nr.) |
copernicus.org/angeo-22-567-2004.pdf |
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Zusammenfassung |
It is well known that the ionosphere plays a role in determining the
global state of the magnetosphere. The ionosphere allows
magnetospheric currents to close, thereby allowing magnetospheric
convection to occur. The amount of current which can be carried
through the ionosphere is mainly determined by the ionospheric
conductivity. This paper starts to quantify the nonlinear
relationship between the ionospheric conductivity and the global state
of the magnetosphere. It is found that the steady-state magnetosphere
acts neither as a current nor as a voltage generator; a uniform Hall
conductance can influence the potential pattern at low latitudes, but
not at high latitude; the EUV generated conductance forces the
currents to close in the sunlight, while the potential is large on the
nightside; the solar generated Hall conductances cause a large
asymmetry between the dawn and dusk potential, which effects the
pressure distribution in the magnetosphere; a uniform polar cap
potential removes some of this asymmetry; the potential difference
between solar minimum and maximum is ∼11%; and the auroral
precipitation can be related to the local field-aligned current
through an exponential function.
Key words. Ionosphere (ionosphere-magnetosphere interactions;
modelling and forecasting; polar ionosphere) |
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