气候变化领域集成服务门户(CCPortal): Eddy Induced Trapping and Homogenization of Freshwater in the Bay of Bengal

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DOI	10.1029/2021JC017180
	Eddy Induced Trapping and Homogenization of Freshwater in the Bay of Bengal
	Paul N.; Sukhatme J.; Sengupta D.; Gayen B.
发表日期	2021
ISSN	21699275
卷号	126 期号:6
英文摘要	Freshwater from rivers influences Indian summer monsoon rainfall and tropical cyclones by stratifying the upper layer and warming the subsurface ocean in the Bay of Bengal (BoB). Here, we use in situ and satellite data with reanalysis to showcase how river water experiences a significant increase in salinity on sub-seasonal timescales. This involves the trapping and homogenization of freshwater by a cyclonic eddy in the Bay. Using a specific example from 2015, river water is shown to enter an eddy along its attracting manifolds within a period of 2 weeks. This leads to the formation of a highly stratified subsurface layer within the eddy. When freshest, the eddy has the largest sea-level anomaly, spins fastest, and supports strong lateral gradients in salinity. Subsequently, observations reveal a progressive increase in salinity inside the eddy within a month. In particular, salty water spirals in, and freshwater is pulled out across the eddy boundary. Lagrangian experiments elucidate this process, whereby horizontal chaotic mixing provides a mechanism for the rapid increase in surface salinity. A salinity budget also suggests that horizontal advection explains much of the change in mixed layer salinity. Further, the adjustment of this freshwater eddy triggers submesoscale dynamics which appear to be an integral part of the process of salinity homogenization. This pathway is distinct from vertical diffusive mixing and is likely to be important for the evolution of salinity in the BoB. © 2021. American Geophysical Union. All Rights Reserved.
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186280
作者单位	Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bangalore, India; Divecha Centre for Climate Change, Indian Institute of Science, Bangalore, India; Mechanical Engineering Department, University of Melbourne, Australia
推荐引用方式 GB/T 7714	Paul N.,Sukhatme J.,Sengupta D.,et al. Eddy Induced Trapping and Homogenization of Freshwater in the Bay of Bengal[J],2021,126(6).
APA	Paul N.,Sukhatme J.,Sengupta D.,&Gayen B..(2021).Eddy Induced Trapping and Homogenization of Freshwater in the Bay of Bengal.Journal of Geophysical Research: Oceans,126(6).
MLA	Paul N.,et al."Eddy Induced Trapping and Homogenization of Freshwater in the Bay of Bengal".Journal of Geophysical Research: Oceans 126.6(2021).