中国东部海域潮汐余流特征及其动力分析  

Characteristics and dynamics of tidal residual circulations in the eastern China seas

作　　者：陈元杰 程鹏 CHEN Yuanjie;CHENG Peng(School of Oceanography,Shanghai Jiao Tong University,Shanghai 200000,China;College of Ocean and Earth Sciences,Xiamen University,Xiamen 361102,China)

机构地区：[1]上海交通大学海洋学院,上海200000 [2]厦门大学海洋与地球学院,福建厦门361102

出　　处：《海洋通报》2021年第4期396-409,共14页Marine Science Bulletin

基　　金：国家自然科学基金(41476004,42076008)。

摘　　要：潮汐余流对中国东部海域物质输运过程起着重要作用。通过对中国东部海域的三维数值模拟,计算了潮汐余流并从潮余涡量角度分析了其形成机制。中国东部海域的欧拉余流在水深较浅的朝鲜半岛沿岸、苏北浅滩、长江浅滩、闽浙沿岸,以及冲绳海槽附近海域,流速量级较大,以余流涡旋的形式呈现,其机制为局部地形差异和潮汐水位高度波动下,科氏效应或摩擦效应导致潮周期内存在净涡量。斯托克斯漂流量级在浅水区较大,而在深水海域则远小于欧拉余流。拉格朗日余流在深水区域与欧拉余流相似,在浅水区域由欧拉余流和斯托克斯漂流共同决定。输运余流和拉格朗日余流分布特征更接近,特别是在近岸海域,但两者的物理意义并不相同。潮汐余流由于常年稳定存在,且在许多海域的流动方向同已知的沿岸流系的方向基本一致,是中国东部海域沿岸流的重要组成部分。估算出了输运余流对沿岸流的贡献率或抑制率,输运余流对近岸陆源沉积物输运和沉积物分布具有不可忽略的作用。Tidal residual currents play an important role in the mass transport in the eastern China seas.Based on the Regional Ocean Modeling System,a three-dimensional numerical model of the eastern China seas was developed to compute tidal residual circulations and tidal residual vorticities.Results show that the Euler residual currents are presented in the form of residual eddy,and the magnitude is lager around the coast of the Korean Peninsula,the bank of North Jiangsu,the Yangtze River bank,the Hangzhou Bay,the coast of the Zhejiang and Fujian Provinces,and the Okinawa trough.The mechanisms for the tidal Euler residual circulation are Coriolis or friction effect caused by the local terrain differences or tidal elevation fluctuations.The magnitude of Stokes drifts is lager in the shallow water regions,but it is much weaker than the Euler residual current in deep water regions.The distribution of Lagrangian residual currents is similar to that of Euler residual currents in deep water regions and is determined by Euler residual currents and Stokes drifts in shallow water regions.The transport residual currents are similar to the Lagrangian residual currents,especially in coastal regions,but their physical meanings are not the same.The tidal residual current is one of the important components of the coastal currents in eastern China seas.The contribution rate or inhibition rate of residual current to coastal current is estimated in the paper.The residual currents play an important role in the transport and distribution of nearshore terrestrial sediments in the eastern China seas.

关 键 词：中国东部海域 潮汐余流 欧拉余流 输运余流 潮余涡量 

分 类 号：P731.21[天文地球—海洋科学]