An instability study of the onset-vortex of the south-west monsoon, 1979.

Abstract

A dry two-layer linear-balanced model is used to investigate the relative effects of the horizontal and vertical shears of the zonal flow over the Arabian Sea in the early phase of the onset of the SW monsoon in 1979. Two aspects of the cyclogenesis which immediately preceded the onset of the monsoon can be adequately accounted for by the process of dynamic instability mainly associated with the horizontal shear of the basic flow. These two aspects are the growth rate and the scale selection of the disturbance.-from Authors