Study of Regional Ocean Circulation Numerical Model and Simulation of the South China Sea Circulation and Water Transport Through Straits

Based on the physical framework of modular ocean model(MOM) and taking the physical process at open boundaries into appropriate consideration, a regional ocean numerical model is developed. In this model, the open boundary conditions can be easily adjusted to meet particular physical conditions at the boundary, and its programs can be easily modified to make the model more reliable. The improved model has many advantages of MOM, such as explicit physical conception, easily understandable formulae and expressive results, and also overcomes some disadvantages of MOM, such as incomplete boundary conditions, difficultly adjustable program and changeable parameters, so the regional model can be run many times faster than the global model and becomes an efficient tool for the regional ocean circulation study. In this paper, the regional model is used for the South China Sea circulation computation by driving the model with climatological wind stress for 10 years to get results with an effect comparable to that of the global model. The simulated results show the seasonal characteristics and multi-eddy structure of the South China Sea current field. The water transport exchanges between the South China Sea and other seas are computed using the simulated current field. On an annual average, the outsea water flows into the South China Sea through the Luzon Strait, and the South China Sea water flows out through the Taiwan Strait, Mindoro Strait and Karimata Strait. The water transports through different straits have obvious seasonal variations.