基于拉格朗日方法的胶州湾物质输运特征研究

利用非结构网格有限体积海洋模型（FVCOM），分析了胶州湾的拉格朗日余流、有限时间Lyapunov指数场（FTLEs）和拉格朗日相干结构（LCSs）的关系。结果表明:胶州湾西部的主要涡旋呈逆时针方向，中部从北向南分布着顺时针、逆时针、顺时针三个涡旋，东岸存在多个逆时针涡旋，大沽河河口、李村河河口和洋河河口存在小的余流涡。与余流结构相对应，在胶州湾内存在南北方向的拉格朗日相干结构的"脊"，"脊"与余流涡旋边界基本重合，是物质输运的通道，并对两侧物质输运起阻隔作用。本文从拉格朗日角度研究了胶州湾污染物输运特征，研究结果可解释污染物浓度局部高值现象，为胶州湾排污口的优化和海洋环境管理提供参考依据。

Study on material transport characteristics in Jiaozhou bay based on Lagrangian method

Based on finite volume community ocean model (FVCOM), this paper simulated Lagrange residual current, finite-time Lyapunov exponents (FTLEs) and Lagrangian coherent structures (LCSs) in Jiaozhou bay.The results show that the main vortices in the west and east of Jiaozhou bay are all anticlockwise, and three vortices, clockwise, anticlockwise and clockwise respectively, spread from north to south in the middle.There are also some small residual vortices in Dagu River estuary, Yanghe River estuary and so on.Corresponding to the residual current structures, the obvious ridges of LCSs in north-south direction exist in Jiaozhou bay.The ridges of LCSs characterize the boundary of the residual vortices and play a barrier role in material transport from one side to the other.This paper clarifies the distribution characteristics of pollutant transport in Jiaozhou bay from the aspect of Lagrangian method.The research results can explain the high concentration phenomenon of pollutant, optimize the site selection of sewage outlets and provide reference for marine environmental management in Jiaozhou bay.