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On the zonal‐scale selection and vertical structure of equatorial intraseasonal waves
Author(s) -
Wang Bin,
Chen Jiukang
Publication year - 1989
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.49711549007
Subject(s) - baroclinity , zonal flow (plasma) , troposphere , wavenumber , kelvin wave , equatorial waves , amplitude , geology , scale (ratio) , atmospheric sciences , geophysics , climatology , mechanics , physics , geodesy , equator , latitude , plasma , quantum mechanics , optics , tokamak
Observed tropical intraseasonal oscillations exhibit a preferential zonal scale of wavenumber one or two and a baroclinic structure with largest flow field amplitude in the upper troposphere. Unstable interaction of boundary layer friction‐induced moisture convergence with condensational heating could cause the scale selection and result in the asymmetric baroclinic structure by means of coupling of vertical normal modes. A vertically continuous linear model describing two‐dimensional equatorial motion demonstrates this feedback mechanism and permits detailed study of vertical structure of unstable moist Kelvin waves.