All Physics Faculty Publications

Document Type

Article

Journal/Book Title/Conference

Annales Geophysicae

Volume

27

Issue

ISEA Special Issue

Publisher

European Geosciences Union

Publication Date

8-2009

First Page

3213

Last Page

3224

DOI

10.5194/angeo-27-3213-2009

Abstract

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.

Comments

Published by European Geosciences Union in Annales Geophysicae.

http://www.ann-geophys.net/27/3213/2009/angeo-27-3213-2009.html

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