Response of Planetary Waves to Stationary Tropical Heating in a Global Atmosphere with Meridional and Vertical Shear

Open Access
Publisher Website
Google Scholar
Abstract
The response of planetary waves to stationary tropical heating in a stratified global atmosphere linearized with respect to a basic zonal mean flow is investigated. The basic zonal wind has meridional and vertical shear. The basic equations are solved by using the method of three-dimensional normal-mode expansion. Forced solutions to a prescribed tropospheric equatorial heating distribution with a specific wavenumber in longitude are examined. Without the basic zonal flow, the internal vertical modes whose equivalent depths are on the order of a few hundred meters are favorably excited, but the response of the external mode (“barotropic” mode) is relatively small. With the inclusion of a zonal flow, the vertical shear of the zonal wind permits the coupling of the external mode with the internal vertical modes. As a result of the coupling, a significant response occurs in the external mode due to the excitation of the “baroclinic” internal modes by tropical heating. The meridional structures of in... Abstract The response of planetary waves to stationary tropical heating in a stratified global atmosphere linearized with respect to a basic zonal mean flow is investigated. The basic zonal wind has meridional and vertical shear. The basic equations are solved by using the method of three-dimensional normal-mode expansion. Forced solutions to a prescribed tropospheric equatorial heating distribution with a specific wavenumber in longitude are examined. Without the basic zonal flow, the internal vertical modes whose equivalent depths are on the order of a few hundred meters are favorably excited, but the response of the external mode (“barotropic” mode) is relatively small. With the inclusion of a zonal flow, the vertical shear of the zonal wind permits the coupling of the external mode with the internal vertical modes. As a result of the coupling, a significant response occurs in the external mode due to the excitation of the “baroclinic” internal modes by tropical heating. The meridional structures of in...

This publication has 0 references indexed in Scilit: