INNER AND OUTER STRUCTURES OF TROPICAL CYCLONE──Ⅰ.BAROTROPIC MODEL

A tropical cyclone is divided into inner and outer regions in which temporal and spacial scales and physical quantities are all different. Making use of the scale analysis and perturbation methods the governing equations of barotropic and baroclinic models are obtained for the two regions, respectively. In the two models the stream and pressure fields are solved analytically and the obtained structrues are approximately consistent with observations. It is shown that there are different governing equations for the inner and outer regions of the tropical cyclone. The inner region is governed by the cyclostrophic wind and an evolution equation, the outer region by the gradient wind and another evolution equation.