Structure and Aanalysi~ of the Eye of a Numerically Simulated tropical Cyclone

A tropical cyclone has been simulated in a qu , druply nested mesh model with finest grid resolution of about S km. At the center of the vol1ex, a compact eye was maintained. Azimuthal means as well as asymmetry of the ye and the eye wall !,tructure are described. The asymmetric features within the eye wall moved cyclonically at a much smaller rotation rate than the cyclonic wind within the eye all. Roles of the mean radial-vertical circulation, the eddy motions and the diffusion effect! in the maintenance of the mean structure are analyzed. In the analysis, attention is give~ to the balance betwec,n the wind and pressure fields and also to the budgets of relative an~ular momentum, heat and water vapor. The eddy motions caused a cooling and moistening ~ffect in the eye which counterbalanced a warming and drying effect due to the mean sinkin~ motion.