冬季黄海暖流的诊断计算

采用ECOMSED三维水动力模式，诊断计算了冬季渤海、黄海和东海的近海环流状况，重点分析了黄海暖流的演变过程及其垂直结构，并探讨了黄海暖流的形成机理。结果表明，黄海暖流于12月初步形成，次年2月发展最强盛，3月开始衰退。黄海暖流在表层和次表层（0-30m）并不是一支持续稳定的流，其持续稳定性仅在近底层得到很好的体现。对黄海暖流形成机理的分析表明，压强梯度力、垂向摩擦力和柯氏力占主要地位。在表层及次表层，主要表现为风的正压作用，而在近底层，则由海平面起伏造成的正压梯度力和密度场引起的斜压梯度力形成的总压强梯度力与柯氏力基本平衡，因而黄海暖流可基本认为是准地转流。

Diagnostic Computation of the Yellow Sea Warm Current in Winter

In this paper,a three-dimensional ECOMSED hydrodynamic model is used to make a(diagnostic) computation of the offshore circulations in the Bohai Sea,Yellow Sea and East China Sea in winter with particular emphasis on the analysis of evolutional process and vertical structure of the Yellow Sea Warm Current(YSWC),and the YSMC formation mechanism is also discussed.It is shown from the analysis results that the YSWC forms in December,reaches its peak in next February,and begins to decline in March.The YSWC in the surface layer and subsurface layer(0~30m) is not a persistent and stable current,and that in the near-bottom layer shows its persistency.It is shown from the analysis of formation mechanism that the pressure gradient force,vertically frictional force and Coriolis force play the leading roles in forming the YSWC.In the surface layer and subsurface layer,the wind-induced barotropic effect plays a leading role,but in the near-bottom layer,the total pressure gradient force generated jointly by the barotsopic pressure force formed by the sea level fluctuation and the baroclinic pressure gradient force formed by density field and Coriolis force play the leading roles,and the total pressure gradient force is basically balanced with Coriolis force,so the YSWC can basically be considered as a quasi-geostrophic current.