A Comparison of Baroclinic Instability with the Time Variations of Kinetic Energy in a General Circulation Model

Abstract

The flow generated by a general circulation model is zonally averaged at 1-day intervals, and, for each of the axisymmetric flows obtained, the linear growth-rate spectrum for baroclinic waves is computed using a linear model. The time sequence of these linear growth-rate spectra is compared to the corresponding time sequence of kinetic-energy spectra for the flow of the general circulation model, in order to-test the hypothesis that the baroclinic instability of the axisymmetric flow is an important factor in determining variations of the amplitudes of the midlatitude eddies. No significant correlation is found between the linear growth rate of a particular wavenumber and the kinetic energy of that wave at some later time.