基于轨迹聚类的南大洋中尺度涡旋主要迁移通道提取与分析  

Extraction and Analysis of Major Migration Channels of Mesoscale Eddy in the Southern Ocean Based on Spatiotemporal Trajectory Clustering

作　　者：郑杰 王绚 马纯永[1,2] 陈戈 Zheng Jie;Wang Xuan;Ma Chunyong;Chen Ge(College of Information Science and Engineering, Ocean University of China, Qingdao 266100, China;The Laboratory for Regional Oceanography and Numerical Modeling, Pilot National Laboratory for Marine Science and Technology(Qingdao), Qingdao 266237, China)

机构地区：[1]中国海洋大学信息科学与工程学院,山东青岛266100 [2]青岛海洋科学与技术试点国家实验室区域海洋动力学与数值模拟功能实验室,山东青岛266237

出　　处：《中国海洋大学学报（自然科学版）》2022年第6期39-49,共11页Periodical of Ocean University of China

基　　金：山东省国际合作重大专项(2019GHZ023);国家自然科学基金项目(41906155,42030406,41527901)资助。

摘　　要：中尺度涡旋在世界各大洋中广泛存在,对海洋物质能量的输送以及海洋与大气间的能量交换起着重要作用。南大洋区域中尺度涡旋的活动受海底地形、流场、风场等多重因素的影响,呈现出一些独特的移动规律。为了高效、准确地得到南大洋区域中尺度涡旋的移动特征,本文提出基于方向的轨迹时空聚类算法。首先,采用最小描述原则将涡旋轨迹按照特征点划分为多条线段;其次,在时空聚类的基础上提出阈值确定原则和方向距离的度量方法,对涡旋线段进行聚类;最后,根据聚类结果提取涡旋迁移通道。实验结果表明,45°S以北均为西向的涡旋迁移通道,45°S以南均为东向的涡旋迁移通道,这与大洋环流的流向基本一致;从涡旋迁移通道的统计特征来看,西向所包含的涡旋在南半球的夏季达到峰值,东向所包含的涡旋在冬季达到峰值,东向所包含涡旋的涡旋动能比西向高;从涡旋的性质来看,在南大洋区域,暖涡(Anticyclonic Eddy,AE)和冷涡(Cyclonic Eddy,CE)的涡旋迁移通道在统计特征、地理位置和移动方向上都极其相似。Mesoscale eddies exist widely in the world oceans,and play an important role in the transport of ocean matter and the energy exchange between the ocean and atmosphere.The activities of mesoscale eddies in the Southern Ocean are affected by multiple factors,such as seabed topography,flow field,and wind field,etc.Which show some unique movement features.In order to efficiently and accurately obtain the movement characteristics of mesoscale eddies in the Southern Ocean region,a direction-based trajectory spatial-temporal clustering algorithm is proposed in this paper.Firstly,the eddy trajectory is divided into several line segments by the Minimum Description Length(MDL)principle.Secondly,based on the spatial-temporal clustering,the threshold determination principle and the measurement method of the direction distance are proposed to cluster the eddy segments.Finally,eddy migration channels are extracted according to the clustering results.The experimental results show that north of 45°S,there is a westward eddy migration channel,and south of 45°S,there is an eastward eddy migration channel,which is basically consistent with the flow direction of ocean circulation;According to the statistical characteristics of the migration channel of the eddy,the west channels contain eddies reach its peak in summer,and the east one reaches its peak in winter.In addition,the eddy kinetic energy of the eastward channels is higher than that of the westward one;In terms of the nature of eddy,the migration channels of AE and CE in the Southern Ocean are very similar in terms of statistical characteristics,Geographical locations and movement directions.

关 键 词：中尺度涡旋 涡旋迁移通道 轨迹聚类 统计特征 南大洋 

分 类 号：P728.1[天文地球—海洋科学]