BAROCLINIC INSTABILITY AND INDUCED AIR-SEA HEAT-EXCHANGE

A very simplified model of baroclinic waves in a saturated environment, in the presence of heat fluxes at the bottom boundary is studied, along the lines of Emanuel et al. The model uses the linearized geostrophic momemtum approximation and two levels in the vertical, and it is solved separately in the updraft and downdraft regions, allowing for different static stabilities. The use of a slantwise convectively neutral updraft constitutes a parameterization of upright and slantwise convective processes. The boundary fluxes of heat are represented in the form of a linearized draw law for equivalent potential temperature. The results, which include faster growth, higher translational speed and destabilization of shorter scales of motion, are discussed in relation to a previous numerical study of mid-latitude explosive cyclones. A linear dependence of deepening rates on heating rate is also obtained and related to the "normal mode" character of the solutions sought.