Instability of planetary waves in a zonal current

Abstract

 Stability properties of planetary-scale motions in a baroclinic zonal current are studied numerically by means of a simple primitive equation system. Mathematical technique used is a form of the method of the initial value which is employed after Brown, Jr. (1969). Some special devices and extensions are made so as to make it applicable to the primitive equation model.
 It is concluded that all waves are unstable and move always eastward. Results are compared with those of the multi-layer geostrophic model.