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Equatorial waves in steady zonal shear flow
Author(s) -
Plumb R. Alan,
Bell Robert C.
Publication year - 1982
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49710845603
Subject(s) - equator , zonal flow (plasma) , rossby wave , kelvin wave , equatorial waves , dissipation , forcing (mathematics) , physics , geophysics , shear flow , mechanics , geology , amplitude , gravity wave , wave propagation , atmospheric sciences , meteorology , latitude , geodesy , plasma , optics , quantum mechanics , tokamak , thermodynamics
The properties of equatorial Kelvin and mixed Rossby‐gravity waves are investigated in an equatorial beta‐plane model of the lower stratosphere. The basic state and wave amplitudes are assumed to be independent of time; the waves are dissipated by thermal and/or mechanical damping. Particular emphasis is placed on the forcing of the mean flow by the waves. In agreement with earlier studies the latitudinal structure of the mean flow forcing is found to be sensitive to the dissipation mechanism; when the mean state is one of no zonal motion the easterly mixed Rossby‐gravity wave‐induced acceleration of the zonal flow is zero on the equator when only thermal dissipation acts, but maximizes on the equator when dissipation is included. This latter property is also found in the presence of equatorial jets. Results from this model, with its explicit resolution of the wave structure, are compared with those from the multiple‐scales approach of Boyd; good agreement is found.