Topographic-baroclinic instability and formation of Kuroshio current loop

doi:10.1016/j.dynatmoce.2017.11.002

	Topographic-baroclinic instability and formation of Kuroshio current loop
	Guo, Jingsong; Zhang, Zhixin; Xia, Changshui; Guo, Binghuo; Yuan, Yeli
刊名	DYNAMICS OF ATMOSPHERES AND OCEANS
	2018-03
卷号	81 页码:15-29
关键词	Kuroshio current loop Topographic-baroclinic instability Luzon strait Analytical solution
ISSN号	0377-0265
DOI	10.1016/j.dynatmoce.2017.11.002
英文摘要	Using time-series figures of sea-level anomaly and geostrophic currents from merged absolute dynamic topography, we analyzed the formation and evolution of the Kuroshio current loop (KCL). The main results are as follows. Perturbation origins of the KCLs are in three areas (eastern, western, and southern) surrounding the Hengchun Submarine Ridge. There are two basic types of KCL formation, i.e., "Kuroshio bend pushing" and "Kuroshio Branch rewinding", plus their combination. The KCLs propagate westward at 1.6-4.5 cm/s. There are two forms of KCL evolution into a shed eddy. The first is such that the northern KCL section initially divides to become an eddy joining the Kuroshio Branch current, which then separates from that current to become a shed eddy. The second form is such that the northern and southern sections of the KCL are separated almost simultaneously in westward elongated process. To understand the KCL formation mechanism, we derive linear equations in phase space from the governing equations in sigma-coordinates, ultimately obtaining two groups of analytical solutions for interactions between waves, topography, and the basic current field. The solutions lead to the following results. The KCL propagates westward with the group velocity of the Kuroshio center region. The Kuroshio generally sweeps over the Hengchun Submarine Ridge, especially in winter, such that there is topographic-baroclinic instability. The analytical solutions effectively reveal the dynamic mechanism of the two basic types of KCL formation. (C) 2017 The Authors. Published by Elsevier B.V.
资助项目	National Natural Science Foundation of China[41206025]
WOS关键词	SOUTH CHINA SEA ; ANTICYCLONIC EDDY ; VARIABILITY ; PACIFIC ; EDDIES
WOS研究方向	Geochemistry & Geophysics ; Meteorology & Atmospheric Sciences ; Oceanography
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000429753500002
内容类型	期刊论文
源URL	[http://ir.fio.com.cn:8080/handle/2SI8HI0U/27501]
专题	自然资源部第一海洋研究所
通讯作者	Xia, Changshui
作者单位	State Ocean Adm, Inst Oceanog 1, Qingdao Natl Lab Marine Sci & Technol, Lab Reg Oceanog & Numer Modeling, Qingdao 266061, Peoples R China
推荐引用方式 GB/T 7714	Guo, Jingsong,Zhang, Zhixin,Xia, Changshui,et al. Topographic-baroclinic instability and formation of Kuroshio current loop[J]. DYNAMICS OF ATMOSPHERES AND OCEANS,2018,81:15-29.
APA	Guo, Jingsong,Zhang, Zhixin,Xia, Changshui,Guo, Binghuo,&Yuan, Yeli.(2018).Topographic-baroclinic instability and formation of Kuroshio current loop.DYNAMICS OF ATMOSPHERES AND OCEANS,81,15-29.
MLA	Guo, Jingsong,et al."Topographic-baroclinic instability and formation of Kuroshio current loop".DYNAMICS OF ATMOSPHERES AND OCEANS 81(2018):15-29.