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Titel |
Comparison of methods to determine auroral ionospheric conductances using ground-based optical and riometer data |
VerfasserIn |
A. Senior, M. J. Kosch, F. Honary |
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 ; 26, no. 12 ; Nr. 26, no. 12 (2008-12-02), S.3831-3840 |
Datensatznummer |
250016313
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Publikation (Nr.) |
copernicus.org/angeo-26-3831-2008.pdf |
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Zusammenfassung |
Ground-based images of auroral optical emissions and cosmic radio
noise absorption provide information on particle precipitation which
enhances ionospheric conductances. Knowledge of this conductance field
is important to understand the current systems associated with auroral
features. Three methods of using ground-based optical and riometer data to
estimate ionospheric conductances in the aurora are compared to
conductances derived from incoherent scatter radar measurements. It is
shown that a method using the 557.7 nm emission intensity alone gives
the best results for the Pedersen conductance whilst a method using
both this intensity and cosmic noise absorption is best for the Hall
conductance. A method using cosmic noise absorption alone gives
reasonable performance for the Hall conductance and the Hall/Pedersen
conductance ratio, but performs poorly for the Pedersen
conductance. It also appears to underestimate the Hall conductance
significantly during times when softer precipitation is present, for
example in discrete auroral arcs. There is some indication that the
methods do not degrade noticeably for angles up to ~20°
off magnetic zenith. |
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