Narrow Results

Although the dramatic increase in computational power, a complete description of the Earth's climate by means of solutions of the equations of motion is far from being achieved. Most of the problems arise because the solutions depend on the second order effects of the dynamic and thermodynamic instability processes that plague the system. These instabilities are such that the observed behavior strongly departs from the response of the atmosphere to the forcing associated with the energy input. In illustrating the nature of the problem, we shall discuss the Atmospheric General Circulation, i.e. the circulation obtained by averaging the atmospheric motion along the longitude. We will show, by considering both the observed motion and some theoretical models, that the solution requires the parameterization of the momentum and heat fluxes associated with the baroclinic instability of the full three dimensional field. We will discuss how the parameterizations strongly depend on the detailed nature of the external parameters. As a conclusion, some speculations on the nature of the closure needed for this problem will be offered.