Symmetric instability of monsoon zonal flows

V. KRISNAKUMAR, R.N. KESHAVAMURTI

Abstract

We have examined the possibility of symmetric instability using a set of zonally symmetric linear perturbation equations in the near equatorial monsoon region incorporating moist convection. In the dry model as well as moist model both unstable and neutral modes were obtained. The unstable modes have period of around 1 to 2 days and with doubling times of around 1 to 2 days. The amplitude structure of such unstable modes are mainly confined to the equatorial regions. Thus we have shown that zonal flows in the monsoon region exhibit symmetric instability.

Full Text:

pdf