Linear modes and storm tracks in a two-level primitive equation model

Abstract

Two sets of experiments are performed: the first with one mountain and the second with three mountains at equal distance from each other. Structures of streamfunctions and heat fluxes from the linearly unstable normal mode are compared with their bandpass transient counterparts in the nonlinear model simulation. For the three mountain cases, there is reasonable agreement between the linear mode and the bandpass transient eddies in terms of both the longitudinal location of the largest eddy amplitudes and the potential enstrophy budget, suggesting that the global mode can capture the correct structure of the climatological storm tracks for different reasons. For the one mountain case, however, the largest eddy amplitude of the linear mode extends farther downstream than that of the bandpass transient eddies. -from Author