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| Titel |
Analysis and modeling of ducted and evanescent gravity waves observed in the Hawaiian airglow |
| VerfasserIn |
D. B. Simkhada, J. B. Snively, M. J. Taylor, S. J. Franke |
| 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 ; 27, no. 8 ; Nr. 27, no. 8 (2009-08-19), S.3213-3224 |
| Datensatznummer |
250016626
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| Publikation (Nr.) |
 copernicus.org/angeo-27-3213-2009.pdf |
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| Zusammenfassung |
| Short-period gravity waves of especially-small horizontal scale have been
observed in the Maui, Hawaii airglow. Typical small-scale gravity wave events
have been investigated, and intrinsic wave propagation characteristics have
been calculated from simultaneous meteor radar wind measurements. Here we
report specific cases where wave structure is significantly determined by the
local wind structure, and where wave characteristics are consistent with
ducted or evanescent waves throughout the mesopause region. Two of the
documented events, exhibiting similar airglow signatures but dramatically
different propagation conditions, are selected for simple numerical modeling
case studies. First, a Doppler-ducted wave trapped within relatively weak
wind flow is examined. Model results confirm that the wave is propagating in
the 85–95 km region, trapped weakly by evanescence above and below. Second,
an evanescent wave in strong wind flow is examined. Model results suggest an
opposite case from the first case study, where the wave is instead trapped
above or below the mesopause region, with strong evanescence arising in the
85–95 km airglow region. Distinct differences between the characteristics of
these visibly-similar wave events demonstrate the need for simultaneous
observations of mesopause winds to properly assess local propagation
conditions. |
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