南海相对涡度的时空变化特征分析  

Spatial-Temporal Features of the Relative Vorticity in the South China Sea

作　　者：袁承仪 匡晓迪[2] 李秀梅 李菲 YUAN Cheng-Yi;KUANG Xiao-Di;LI Xiu-Mei;LI Fei(College of Marine and Environmental Sciences,Tianjin University of Science and Technology,Tianjin 300457,China;National Marine Environmental Forecasting Center,Beijing 10081,China)

机构地区：[1]天津科技大学海洋与环境学院,天津300457 [2]国家海洋环境预报中心,北京100081

出　　处：《中国海洋大学学报（自然科学版）》2019年第11期1-11,共11页Periodical of Ocean University of China

基　　金：国家自然科学基金项目（41606028）;天津市科技计划项目（14JCQNJC09900）;国家重点研发计划项目（2016YFC1401800）;中国科学院环流与波动重点实验室开放基金项目（KLOCWAW1308）资助~~

摘　　要：本文使用2014-2017年间逐日平均的法国Mercator中心全球高分辨率海洋数据集PSY4,探讨南海海域相对涡度与海盆尺度环流的时空变化特征。依照涡度的年平均剖面,在垂向上将南海分为:涡度为正的上层、涡度为负的中层和涡度为正的深层,对应了南海海盆尺度的“气旋式-反气旋式-气旋式”垂向环流。最为显著的相对涡度季节变化出现在南海的上层,最大冬、夏季差异达6.3×10^-7 s^-1,为该层内年平均相对涡度值1.7×10^-7 s^-1的3.7倍。在该层的内部,依照季节变化的幅度大小可以进一步划分为3个子层,其中季节变化幅度最大的为上200 m层。在中、深层,深度积分的涡度与海盆尺度环流分别具有“冬强夏弱”和“冬弱夏强”的季节变化特征,而涡度的年际差异可以与季节差异同等重要;逐月的涡度时间序列与吕宋海峡不同断面的水通量变化具有统计相关。Spatial and temporal features of the relative vorticity and basin-scale circulation in the South China Sea(SCS)are investigated using daily fields of the PSY4 dataset derived from a high-resolution global ocean model produced by Mercator-Ocean in France.According to the vertical profile of annual mean vorticity,the water column of the SCS can be divided into the upper,middle and deep layers with the positive-negative-positive vorticity,respectively,which are consistent with a vertical structure of cyclonic-anticyclonic-cyclonic circulation.The most significant seasonal variation of the relative vorticity exists in the upper layer of the SCS,with the maximum of 6.3×10^-7 s^-1,which reaches 3.7 times as much as the annual mean vorticity of 1.7×10^-7 s^-1 in this layer.Based on the magnitudes of seasonal variations of the vorticity,the upper layer can be further divided into three sub-layers.In the middle and deep layers,the larger depth-integrated vorticity and the stronger basin-scale circulation occur in the winter and summer season,respectively.In these layers,the year-to-year variations of the relative vorticity are as significant as the seasonal variations.Time series of the monthly mean vorticity are correlated with those of the volume transport through different sections at the Luzon Strait.

关 键 词：涡度 环流 南海 季节变化 PSY4 

分 类 号：P731.21[天文地球—海洋科学]