A new presentation of the Indian Ocean shallow overturning circulation from a vertical perspective  

作　　者：Tiecheng Zhang Weiqiang Wang Qiang Xie Kexiu Liu Dongxiao Wang Xinrong Wu Xiaoshuang Zhang Kang Xu Wenya Yuan 

机构地区：[1]Key Laboratory of State Oceanic Administration for Marine Environmental Information Technology,National Marine Data and Information Service,Ministry of Natural Resources,Tianjin,China [2]State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou,China [3]Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou,China [4]Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences,Guangzhou,China [5]Institute of Deep-sea Science and Engineering,Chinese Academy of Sciences,Sanya,China [6]Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao,China [7]School of Marine Sciences,Sun Yat‐Sen University,Zhuhai,China

出　　处：《Atmospheric and Oceanic Science Letters》2021年第5期56-61,共6页大气和海洋科学快报（英文版）

基　　金：supported by the National Key Research and Development Program of China[grant number 2016YFC1401803];the National Natural Science Foundation of China[grant numbers 41976019 and 42076020];the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDA20060502];the open project of the State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences[grant number LTO1910];the Research Program of the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)[grant number GML2019ZD0306];the Key Research Program of the Chinese Academy of Sciences[grant number ZDRW-XH-2019-2]。

摘　　要：The calculation of the meridional overturning streamfunction in the southern Indian Ocean is biased by the Indonesian Throughflow.Therefore,this study applies the vertical overturning streamfunction to diagnose the shallow overturning circulation in the Indian Ocean.Using the Ocean General Circulation Model for the Earth simulator output,improvements with the vertical overturning streamfunction compared with the meridional overturning streamfunction are explored.The results show that the vertical overturning streamfunction smoothly connects the shallow overturning circulations of the northern Indian Ocean and the southern Indian Ocean with the whole cycle of the subtropical cell and the cross-equatorial cell.The vertical overturning streamfunction shows a much cleaner shallow overturning circulation,which is underestimated by the meridional overturning streamfunction.It shows that the shallow overturning circulation has a magnitude of~13 Sv(1 Sv≡106 m 3 s−1),of which the subtropical cell accounts for~8 Sv.In addition,the vertical overturning streamfunction captures a clockwise overturning cell in the upper 600 m layer between 30°S and 34°S.This cell has a magnitude of about−5 Sv and probably corresponds to the wind-forced subtropical gyre.Therefore,the vertical overturning streamfunction provides a new approach for estimating the shallow overturning circulation in the Indian Ocean.由于印尼贯穿流干扰了南印度洋经向翻转环流的计算,本文应用垂向翻转流函数来诊断印度洋浅层经向翻转环流.基于海洋环流模拟产品(OFES),本文探讨了垂向流函数相比经向翻转流函数的改进.研究结果表明垂向翻转流函数能平滑连接南北印度洋的翻转环流,包括完整的副热带翻转环流和跨赤道翻转环流.经向翻转流函数低估了印度洋浅层翻转环流;而垂向翻转流函数表示的印度洋浅层翻转环流受印尼贯穿流影响更小,其评估的印度洋浅层翻转环流强度约13 Sv,其中副热带翻转环流强度约8 Sv(1 Sv≡10~6m~3S~(-1)).此外,垂向翻转流函数在印度洋南开边界(30°S~34°S)上600 m层表现为顺时针翻转结构,其强度约-5 Sv,可能对应风驱的副热带流系.因此,垂向翻转流函数提供了一种新方法来评估印度洋浅层翻转环流.

关 键 词：Indian Ocean Shallow overturning circulation Meridional overturning streamfunction Vertical overturning streamfunction 

分 类 号：P731.27[天文地球—海洋科学]