Formulation of a semi-geostrophic model of frontal interaction with isolated orography

A semi-geostrophic model of frontal passage over topography was developed t o examine the effects of the interaction of a well developed front with an isolated mountain, and the subsequent orographically induced flow evolution . The analytic representation of the primary wave and its frontal structure gives us the ability to control the environmental and geometrical constrai nts and perform an exploration of parameter space. A number of problems app earing because of this approach are discussed. The results shown relate the characteristics of the orographic perturbation to varying amplitude of the primary wave and varying frontal intensity, but suggest that the represent ation of flow blocking by the mountain, which this model lacks, is crucial for the representation of frontal intensification in the lee of orography.