区域性海洋环流数值模式研究及对南海环流与海峡流量的模拟

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

基于MOM模式的物理框架,妥善考虑了开边界的物理过程,改造和发展了一个区域海洋数值模式。本模式不仅可以方便地调整开边界条件,使之满足边界的特定物理条件,而且可以方便地做针对性修改,使模式更加可靠。改进后的模式具有MOM模式物理概念明确、公式便于理解、结果便于表达的全部特点,同时克服了MOM模式边界条件不完整、程序不易调整、参数难以改变的缺点。区域性模式比全球模式的计算速度快很多倍,可以成为区域性研究的有效工具。将此模式应用于南海,利用Hellerman＆Rosenstein气候态风应力驱动模式10a,得到与全球模式效果相当的结果。模式模拟结果展现了南海流场的季节特征,在模式分辨率下表现出了多涡结构。根据模拟的流场计算了南海与其它海域的水交换通量。在年平均意义下,外海水通过吕宋海峡进入南海,南海水通过台湾海峡、民都洛海峡和卡里马塔海峡流出南海。各海峡水通量具有明显的季节变化。

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.