Some Characteristic Features of the Large-Scale Disturbance in a Baroclinic Zonal Current

Abstract

In order to know the energy cycle of the baroclinic disturbance in a zonal flow, the two-level geostrophic model with the adiabatic and hydrostatic assumptions was integrated for long time period. The 6 components of the trigonometric function were used to represent the broad-scale features of the motions in the model atmosphere. Time behaviours of the energy transformation functions, meridional transport of sensible heat and eddy zonal momentum associated with the development of the baroclinic wave are followed and analysed. The dependencies of energy cycle upon the scale of the disturbance and the zonal vertical shear are examined by changing the zonal wave number from 14 to 1. The period of the energy cycle which is mainly governed by the baroclinic process, is of the order of a week or ten days, however, the occurrence of the considerably long time period is possible, if the initial assignment of the vertical zonal shear is close to the critical value to create the baroclinic instability.