A mathematical model for the 3-D dynamics of lee wave across a meso-scale mountain corner

Abstract

A mathematical model for studying the 3-D dynamical structure of lee wave across a meso-scale mountain corner has been proposed for a mean flow with realistic vertical variation of wind and temperature. The basic flow consists of both zonal wind component (U) and meridional component (V), which are assumed to be dependent of height. The Brunt-Vaisala frequency (N) is also assumed to be dependent of height. This model has been applied to the mountain corner, in the North East India, formed by broadly North-South oriented Assam Burma Hills (ABH) and broadly               East-West oriented Khasi Jayantia hills (KJH). The model has been solved following the quasi-numerical approach. The perturbation vertical velocity  is expressed as a double integral. Three cases have been studied and in all cases the relation between the possible transverse and divergent lee wave numbers (k, l) and also the updraft/downdraft regions associated with lee waves at different heights has been mapped and discussed.