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Titel |
Excitation of the ionospheric resonance cavity by neutral winds at middle latitudes |
VerfasserIn |
V. V. Surkov, O. A. Pokhotelov, M. Parrot, E. N. Fedorov, M. Hayakawa |
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. 8 ; Nr. 22, no. 8 (2004-09-07), S.2877-2889 |
Datensatznummer |
250014972
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Publikation (Nr.) |
copernicus.org/angeo-22-2877-2004.pdf |
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Zusammenfassung |
A new mechanism for the ionospheric Alfvén
resonator (IAR) excitation at middle latitudes is considered. It is shown
that the ionosphere wind system in this region is capable of sustaining the
generation of geomagnetic perturbations that can be detected by ground
magnetometers. The general IAR dispersion relation describing the linear
coupling of the shear Alfvén and fast magnetosonic/compressional modes
is obtained. The dependence of the IAR eigenfrequencies and damping rates on
the perpendicular wave number and on the ground conductivity during the
day- and nighttime conditions is analyzed both analytically and numerically. In
order to demonstrate the IAR excitation by neutral winds the power spectra
of the geomagnetic perturbation on the ground surface are calculated.
Furthermore, it is found that Kolmogorov spectra of the ionospheric
turbulent neutral winds and the IAR eigenfrequencies lie in the same
frequency range that make it possible to enhance the IAR excitation. The
relevance of the developed theoretical model to the ground-based
observations is stressed. |
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