| An eighteen level axisymmetric primitive equation tropical cyclone model which incorporates the Arakawa-Schubert (1974) spectral cumulus parameterization is presented. The quasi-equilibrium hypothesis, which involves the solution of an integral equation for the cloud base mass flux distribution, is successfully formulated as an optimization problem to guarantee a nonnegative solution. A linear analysis suggests that in the tropics a large fraction of the available potential energy generated by the release of latent heat is partitioned to gravity-inertia wave motion and hence is radiated away to the far field. Therefore, an approximate pure gravity wave radiation boundary condition is derived which minimizes the reflection of gravity-inertia waves by the lateral boundary of the model.; The sensitivity of axisymmetric model storm development to the exact form of the lateral boundary condition, initial moisture distribution, and latent heat release mechanism is tested. It is demonstrated that the development of a hurricane-like circulation can be simulated without parameterized convection as suggested by Rosenthal (1978). Several other sensitivity experiments are conducted to address the roles of radiation and cumulus momentum transport in tropical cyclone development. The numerical results lead to the conclusion that neither of these processes should be neglected in attempts to numerically simulate the life cycle of the tropical cyclone since they appear to contribute significantly to the organization and scale of tropical disturbances. |
