THE DYNAMICAL BASIS OF GEOSTROPHIC ADJUSTMENT MOTIONS IN TROPICS^*

Some dynamic constrains in the process of the tropical baroclinic geostrophic adjustment are discussed.The dispersion equation of three-dimensional inertia-gravitational wave and the equation of temporal conservation of potential vorticity are given,without considering the gradient of planetary potential vorticity.It indicates that the motions will be horizontal,meaning that Taylor-Proudman theorem is still right for tropics.At the same time,the semi-geostrophic balance is easier to appear in the tropical belt.Therefore the motions are generally horizontal and non-divergent,but still are stratified after the geostrophic balance establishes.