南海中尺度涡的形转、内转及平移运动研究  

The migration,circulation and rotation of mesoscale eddy in the South China Sea

作　　者：杨雪晴 韩贵艳 田丰林[1,2] 马纯永 王帅[3,4] 陈戈 YANG Xueqing;HAN Guiyan;TIAN Fenglin;MA Chunyong;WANG Shuai;CHEN Ge(Department of Marine Technology,College of Information Science and Engineering,Ocean University of China,Qingdao 266100,China;Laboratory for Regional Oceanography and Numerical Modeling,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266200,China;Department of Physics,Imperial College London,London SW72AZ,UK;State Key Laboratoryof Satellite Ocean Environment Dynamics,Second Institute Of Oceanography MNR,Hangzhou 310012,China;Institute for Advanced Ocean Study,Ocean University of China,Qingdao 266100,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266200 [3]帝国理工学院物理系,英国伦敦SW72AZ [4]自然资源部第二海洋研究所卫星海洋环境动力学国家重点实验室,浙江杭州310012 [5]中国海洋大学海洋高等研究院,山东青岛266100

出　　处：《海洋通报》2020年第5期536-547,共12页Marine Science Bulletin

基　　金：国家自然科学基金(42030406);山东省支持青岛海洋科学与技术试点国家实验室重大科技专项(2018SDKJ0102)。

摘　　要：中尺度涡旋的运动整体可分为两部分:平移及转动。平移指涡旋在整个生命周期内的水平移动,而转动除了包括内转(海表地转流引起的涡旋自身水体转动)外,还包括形转(涡旋实际边界最佳拟合椭圆的转动)。本文基于1993—2018年共计26年间的卫星高度计涡旋识别与追踪数据,首次对南海中尺度涡旋的完整运动形式,即形转、内转、平移展开了系统的研究。其中,对内转及平移的分析,可通过涡旋的识别追踪数据集直接进行;为研究涡旋形转,提出了一种基于涡旋识别追踪数据自动提取涡旋形转信息的算法,以此得到涡旋形转方向、每天形转的角度以及形转圈数等信息,获得涡旋形转数据集。通过对涡旋识别追踪数据以及形转数据集的统计分析发现:南海涡旋的平移方向多为西向,且其速率呈偏态分布,主要以南海南部偏高。同样,涡旋的内转速率也呈偏态分布,高速率内转的涡旋主要分布在吕宋海峡附近。涡旋的形转主要以南海南部速率偏高,且与涡旋的寿命及长轴有一定的关系,倾向于随着涡旋寿命的增长、涡旋长轴的增大而变慢。同时南海涡旋的这三种不同运动形式之间也存在一定的相关性。The motion of mesoscale eddy can be divided into two parts:migration and rotation.Migration refers to the horizontal movement of the eddy core in the whole life cycle,and the rotation includes not only the internal circulation(caused by the geostrophic flow),but also the overall rotation(the rotation of the best-fitted ellipse of the eddy boundary).Based on the eddy recognition and tracking data obtained from satellite altimeter for 26 years from 1993 to 2018,this paper has studied the complete motion forms of the mesoscale eddy in the South China Sea,i.e.migration,internal circulation and overall rotation,for the first time.Among them,the analysis of migration and internal circulation can be directly carried out through the identification and tracking data set of eddies;In order to study the eddy overall rotation,we propose an algorithm to automatically extract the information of eddy overall rotation based on the identification and tracking data of eddies,such as the overall rotation direction,the overall rotation angle per day and the number of the overall rotation,thus we can obtain a dataset of eddy overall rotation.Through the statistical analysis of these two datasets,it is found that eddy in the South China Sea is mostly propagating westward.Its speed is in a skewed distribution,and the eddies with a high migration speed is mainly located in the south of the South China Sea.Similarly,the internal circulation speed is also in a skewed distribution,and the eddies with a high circulation speed is mainly located near the Luzon Strait.In the south of the South China Sea,the overall rotation speed of the eddy is relatively high.There is a certain relationship between the eddy overall rotation speed and its lifetime and scale,that is,the speed tends to decrease with the increase of eddy life and the increase of the long axis.Meanwhile,there is a certain correlation between these three different forms of motion of eddies in the South China Sea.

关 键 词：南海 中尺度涡旋 形转 内转 平移 

分 类 号：P731.2[天文地球—海洋科学] P722.7