that was caused by coastally trapped waves generated by boreal late spring wind along the south western coast Australia. This means that the flow from Pacific to Indian ocean can be generated by late spring monsoonal wind and is significant in in the eastern rout, i.e. Banda Sea and Timor sea.
Recently Miyama et al.[1995] used 19 level with 0.5 degree resolution Indo-Pacific ocean [10E-60W, 65S-40N] robust diagnostic model to study seasonal transport variations between the Pacific and Indian Oceans. Since the model is diagnostic, the approximations of rigid-lid, Bousinesq, and the hydrostatic balance were employed and the fixed value of 130 Sv was used as open boundary conditions at the western and eastern boundaries for the Antarctic Circumpolar Current (ACC). The total volume transport was estimated to be 20 Sv. They pointed out that subsurface throughfiow occurs from spring to winter, and the deep layer quasi-steady transport of Pacific water into the eastern rout (Banda sea) was fed by the western deep current in the equatorial Pacific.
In this study a diabatic ocean general circulation model formulated on isopycnal coordinate is used to simulate the Indo-Pacific Throughflow. It is compelling to study how this type of model compares with the classic z-coordinate models of ocean circulation. The primary interest in using isopycnal models is that mixing in the interior ocean is usually considered to occur predominantly along isopycnals. This model can therefore be viewed as being built in a more natural geometry than vertical grid z-grid point models, because the layer coordinate correspond to surface of strongest lateral mixing. Cross-isopycnal mixing processes can then be more precisely controled in the layer model. At the air-sea interface, strong vertical mixing occurs which result in surface mixed layers. In this layer model, the turbulent surface mixed layer is modeled after the bulk formalization and is coupled to the underlying isopycnal layers.
In section 2, the ocean model used in this study will be briefly described, and the atmospheric fluxes used to force trhe ocean model. Section 3 contains numerical results. Discussion and samary wil be stated in section 4.
2. The Ocean Model
The global isopycnal model with embeded mixed layer (designated as OPYC) which is used in this study is a revised and extended version of the model developed by Oberhuber [1986, 1990]. The interior of the ocean comprises twelve isopycnal layers. The embeded bulk surface mixed layer model is a descendant of the formulation of Kraus and Turner [1967]. The model is coded in a very versatile fashion allowing arbitrary geometry, topography, and discritization to be specified for flow on a sphere. Extensive discussions of the numerical schemes and details of the model formulation are given by Oberhuber [1986. 1990,1993a, 1993b] and Miller et al. [1991]. In summary, the model consists of four components: a model for the deep ocean that uses isopycnal coordinates, an actively coupled mixed-layer model,
