Rossby normal modes in nonuniform background configurations. Part I: simple fields.

The influence of mean field variations on the realization of planetary normal modes is investigated by examining the mode response and structure in the presence of simple background nonuniformities. Gradients in the mean wind and temperature fields have the collective effect of depressing, shifting and broadening the characteristic response. While nonuniformities in both the wind and temperature fields contribute to the reduction in resonant response, spectral shifting and broadening are induced principally by variations in the mean wind field.-from Author