Low level wind shear and baroclinic growth of monsoon depression scale waves

Abstract

A quasi-geostrophic, linear stability analysis was carried out to find the effect of low level wind shear on the baroclinic growth of monsoon depression scale waves. The low level wind shear of the mean monsoon flow is altered by varying the surface wind, the position and the magnitude of the westerly maximum. The growth rate and phase velocity of the short unstable waves for all the cases of wind profiles are obtained. It is noticed that the growth rate and phase velocity of the depression scale waves (L≈2000 to 2500 km) are not influenced by small variations in the position or magnitude of the westerly maximum. But the growth rate of depression scale waves does depend on the average wind shear between 850-500 mb region.