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Latitude-dependent finescale turbulent shear generations in the Pacific tropical-extratropical upper ocean

Turbulent mixing, which is critically important for the equilibrium of ocean circulation, is controlled by finescale turbulent shear (S(2)) of oceanic flows through shear instability. Although the relationship between S(2) and mixing is well understood, the latitude-dependent generation processes of...

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Autores principales: Zhang, Zhiwei, Qiu, Bo, Tian, Jiwei, Zhao, Wei, Huang, Xiaodong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6173738/
https://www.ncbi.nlm.nih.gov/pubmed/30291235
http://dx.doi.org/10.1038/s41467-018-06260-8
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author Zhang, Zhiwei
Qiu, Bo
Tian, Jiwei
Zhao, Wei
Huang, Xiaodong
author_facet Zhang, Zhiwei
Qiu, Bo
Tian, Jiwei
Zhao, Wei
Huang, Xiaodong
author_sort Zhang, Zhiwei
collection PubMed
description Turbulent mixing, which is critically important for the equilibrium of ocean circulation, is controlled by finescale turbulent shear (S(2)) of oceanic flows through shear instability. Although the relationship between S(2) and mixing is well understood, the latitude-dependent generation processes of S(2) remain poorly known due to the lack of geographically extensive, long-term finescale velocity measurements. Here, using one-year ADCP data from 17 moorings along 143°E, we first show that the upper-ocean S(2) and its resultant mixing rate have a W-shaped latitudinal distribution in the tropical-extratropical northwest Pacific with peaks at 0–2°N, 12–14°N, and 20–22°N, respectively. Further analyses reveal that these S(2) peaks are caused by vertically-sheared equatorial currents, parametric subharmonic instability of diurnal tide, and anticyclonic eddy’s inertial chimney effect, respectively. As climate model simulations are sensitive to the mixing parameterizations, our findings highlight the need to incorporate the latitude-dependent generation mechanisms of S(2) to improve climate models’ prediction capabilities.
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spelling pubmed-61737382018-10-09 Latitude-dependent finescale turbulent shear generations in the Pacific tropical-extratropical upper ocean Zhang, Zhiwei Qiu, Bo Tian, Jiwei Zhao, Wei Huang, Xiaodong Nat Commun Article Turbulent mixing, which is critically important for the equilibrium of ocean circulation, is controlled by finescale turbulent shear (S(2)) of oceanic flows through shear instability. Although the relationship between S(2) and mixing is well understood, the latitude-dependent generation processes of S(2) remain poorly known due to the lack of geographically extensive, long-term finescale velocity measurements. Here, using one-year ADCP data from 17 moorings along 143°E, we first show that the upper-ocean S(2) and its resultant mixing rate have a W-shaped latitudinal distribution in the tropical-extratropical northwest Pacific with peaks at 0–2°N, 12–14°N, and 20–22°N, respectively. Further analyses reveal that these S(2) peaks are caused by vertically-sheared equatorial currents, parametric subharmonic instability of diurnal tide, and anticyclonic eddy’s inertial chimney effect, respectively. As climate model simulations are sensitive to the mixing parameterizations, our findings highlight the need to incorporate the latitude-dependent generation mechanisms of S(2) to improve climate models’ prediction capabilities. Nature Publishing Group UK 2018-10-05 /pmc/articles/PMC6173738/ /pubmed/30291235 http://dx.doi.org/10.1038/s41467-018-06260-8 Text en © The Author(s) 2018 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Zhang, Zhiwei
Qiu, Bo
Tian, Jiwei
Zhao, Wei
Huang, Xiaodong
Latitude-dependent finescale turbulent shear generations in the Pacific tropical-extratropical upper ocean
title Latitude-dependent finescale turbulent shear generations in the Pacific tropical-extratropical upper ocean
title_full Latitude-dependent finescale turbulent shear generations in the Pacific tropical-extratropical upper ocean
title_fullStr Latitude-dependent finescale turbulent shear generations in the Pacific tropical-extratropical upper ocean
title_full_unstemmed Latitude-dependent finescale turbulent shear generations in the Pacific tropical-extratropical upper ocean
title_short Latitude-dependent finescale turbulent shear generations in the Pacific tropical-extratropical upper ocean
title_sort latitude-dependent finescale turbulent shear generations in the pacific tropical-extratropical upper ocean
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6173738/
https://www.ncbi.nlm.nih.gov/pubmed/30291235
http://dx.doi.org/10.1038/s41467-018-06260-8
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