A Numerical Iiivestigation of Certain Features of the General Circulation

The space variables of a two-layer, quasi-geostrophic model, which includes non-adiabatic terms and a variable static stability, are expanded in a few leading terms of a spherical harmonic series. The terms are chosen to specify a zonal current with a belt of easterlies and westerlies, and a single baroclinic wave. These expansions are used to transform the equations of the model into a set of thirteen ordinary differential equations. Numerical experiments have been carried out with this system for different wave lengths of disturbance and different levels of heating contrast. The solutions indicate that the system combines many effects noted in the “dishpan” experiments and theoretical stability studies of large-scale motions.