On the dynamics of a storm track

Abstract

An idealized primitive equation model is used to show that localized regions of enhanced baroclinicity do not necessarily lead to localization of eddy activity. By studying the energetics of the storm track, it is shown that while baroclinic conversion does indeed correlate with the region of maximum baroclinicity, it is the downstream radiation of energy through the ageostrophic geopotential fluxes which acts as a trigger for the development and maintenance of eddy activity over less baroclinic regions. Examples of eddy life cycles are given that show that convergence and divergence of ageostrophic fluxes can dominate baroclinic and barotropic conversion, especially in regions with weak baroclinicity. Factors that may limit the zonal extent of a storm track are discussed. -from Authors