温度、盐度和风应力对南海海流模拟的影响

INFLUENCES OF SEA TEMPERATURE, SOLINITY AND WIND STRESS ON SIMULATIONS OF OCEANIC CURRENTS IN THE SOUTH CHINA SEA

用美国普林斯顿大学海洋模式（ＰＯＭ）对南中国海的年平均海流进行了数值模拟，对温盐结构和风应力在海流形成中的作用进行了较详细的讨论。结果表明，仅有温盐水平不均匀分布也可以驱动海水而生成南海海流，但此种海流的结构较乱，最大流速只有３０～４０ｃｍ·ｓ－１。若温盐无水平结构，则在风应力驱动下，南海海流的结构较为有序，且最大流速可增至６０～７０ｃｍ·ｓ－１。在温盐水平分布不均匀并有风应力的作用时，生成的南海海流与仅有风应力作用时的海流场较相似，说明在南海海流的形成中，风应力的作用更为重要。海面自由高度的分析也证明了上述结论。

Numerical simulations of the annual mean oceanic currents in the South China Sea(SCS) are carried out by use of the USA. Princeton University Ocean Model(POM). The effects of the structures of sea temperature (ST) and salinity (S) and the wind stress on the formation of the oceanic currents are discussed in this paper in some detail. Results show that the SCS oceanic currents can be driven by the horizontally non-uniform distribution of ST and S alone, however, the structure of such currents is in somewhat disorder, and the maximum speed is only 30￣40 cm·s -1 . If the ST and S have no horizontal structure, the only wind stress drives the ocean to form orderly currents, and the maximum speed increases to 60￣70 cm·s -1 . With both the non-uniform structures of ST and S and the wind stress, the currents formed are more similar to those driven only by the wind stress. It means that the wind stress is more important in the formation of ocean currents. The analysis of the free sea surface height also proves the above conclusions.