引用本文:	赵保仁,曹德明.渤海冬季环流形成机制动力学分析及数值研究.海洋与湖沼,1998,29(1):86-96.

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渤海冬季环流形成机制动力学分析及数值研究
赵保仁^1,2, 曹德明^1,2
1.中国科学院海洋研究所青岛;266071

摘要:

采用涡度方程、海面实测风应力分布和二维数值方法，对渤海冬季环流形成机制进行了研究。结果表明，渤海冬季海面风应力分布东岸大、西岸小，又因海底十分平坦，从而风应力切变形成的负涡度，成为渤海中部及辽东湾海流是顺时外向流动的主要驱动机制。当考虑海面实测风应力分布、潮余流和开边界入流等条件时，用二维数值方法模拟的渤海冬季环流，与实测吻合良好。一系列数值实验进一步表明：上述关于渤海环流形成机制的动力学分析是正确的；潮余流对黄河三角洲外海的北－东北向海流有重要贡献；海峡处北进、南出的流场是由冬季季风与北深、南浅的海底地形共同作用的结果。

关键词: 渤海环流动力学分析数值模拟形成机制

DOI：

分类号:

基金项目:国家重点基金及院重点项目资助，4914005号

附件

DYNAMIC ANALYSIS AND NUMERICAL MODELING OF FORMING MECHANISMS OF WINTER CIRCULATIONS IN THE BOHAI SEA

ZHAO Bao-ren,CAO De-ming

Institute of Oceanology, The Chinese Academy of Sciences, Qingdao, 266071

Abstract:

With the vorticity equation, measured mean surface wind velocity and two-dimensional numerical model, forming mechanisms of winter circulation of the Bohai Sea are presented. Because of small horizontal variation of water density in winter and of very plain bottom, the wind stress becomes the only main acting force to drive the winter circulation of the Bohai Sea. From Zhang et al’s (1983) statistical wind field data of the Bohai Sea it is found that the wind stress in its eastern part is obviously larger than in its western part in winters. Calculations show that the averaged vorticity of wind stress is about -0.67×10^-7 N/m³. So on the basis of the vorticity equation

the negative vorticity of horizontal shear of the wind stress must drive the clockwise circulation in the center part of the Bohai Sea and in Liaodong Bay. But most of the present numerical models of Bohai Sea winter circulation, using constant wind velocity, produce anticlockwise water movement in its main part, which does not agree at all with measurements. Because these models ignored the above horizontal shear of wind stress. Using two-dimensional numerical model, and taking into account the effects of the measured wind stress distribution, tidal current and inflow at the open boundary, the Bohai sea winter circulations is successfully modeled and obtained current pattern is almost the same as that measured. A series of numerical model tests showed that our dynamic analyses of the forming mechanism of winter circulations is completely correct; that horizontal shear vorticity really induces the clockwise circulation in the main part of the Bohai Sea and in the Liaodong Bay; that tidal residual currents make important contribution to the north-northeastward current in the Yellow River Delta offshore; that the Bohai Strait flow pattern (inflow in northern part outflow in southern part) is induced by the of winter monsoon and the deep northern and shallow southern bottom topography in the strait.

Key words: Bohai circulation, Dynamic analysis, Numerical modeling, Forming mechanisms