冬夏季海面风场和海洋表层流的数值计算

NUMERICAL CALCULATIONS OF SEA SURFACE WINDS AND OCEAN SURFACE CURRENTS IN WINTER AND SUMMER

设计了一个海面风场的诊断模式和一个海洋表层流的数值计算模式。只要输入海面气压场并利用迭代方法，即可求得海洋表面的风场和海流场。利用１月和７月多年平均的海平面气压场，对这两个模式的性能进行了检验。结果表明，无论冬夏，用海平面气压场诊断出的海面风场与观测到的海面风场很接近，而与地转风场有很明显的区别。用海面风场和海面气压场启动的海洋表面流，与实况也较一致。本文的试验结果还表明，计算海流时，不应忽略海平面气压场的作用，因为海面的自由高度梯度几乎被海平面气压梯度所抵消。

A diagnostic model of the sea surface winds and a computational model of the ocean surface currents are developed in this paper. The sea surface winds and the ocean surface currents can be obtained by iteration method as long as the sea surface level pressure fields are input. The capabilities of the two models are tested by the use of the multiyearly averaged January and July sea surface level pressure fields. Results show that the diagnosed sea surface winds from the sea surface pressure fields are very close to the observations both in winter and in summer, and they are quite different from the geostrophic winds. The ocean surface currents driven by the sea surface winds and the sea surface pressure fields are also close to the observations. From the results it is seen,too, that the sea surface level pressure field should not be neglected when the ocean currents are being computed, for the gradients of the free sea surface heights are almost offset by those of the sea surface pressure fields.① Supported by the Naticnal Natural Science Foundation of China.②