Intensifying stratified turbulence and mixing towards the oceanic submesoscale front

Abstract The role of submesoscale processes as the primary energy source for ocean turbulence remains controversial due to observational limitations. Seismic imaging captures multi-scale processes from mesoscale to finescale, allowing us to infer turbulence processes. This study identified hundreds...

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Main Authors: Qunshu Tang, Jianmin Lin, Wen Xu, Zhiyou Jing, Vincent C. H. Tong
Format: Article
Language:English
Published: Nature Portfolio 2025-05-01
Series:npj Climate and Atmospheric Science
Online Access:https://doi.org/10.1038/s41612-025-01069-x
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author Qunshu Tang
Jianmin Lin
Wen Xu
Zhiyou Jing
Vincent C. H. Tong
author_facet Qunshu Tang
Jianmin Lin
Wen Xu
Zhiyou Jing
Vincent C. H. Tong
author_sort Qunshu Tang
collection DOAJ
description Abstract The role of submesoscale processes as the primary energy source for ocean turbulence remains controversial due to observational limitations. Seismic imaging captures multi-scale processes from mesoscale to finescale, allowing us to infer turbulence processes. This study identified hundreds of ~200-m-long high seismic reflection patches, primarily caused by vertical temperature changes, moving at 0.24 ± 0.13 m/s across the deep-reaching front of Bransfield Current, Antarctica. Patch distribution within the main current is uneven, increasing exponentially towards the frontal leading edge. Over 95% of the detected patches are concentrated within 10 km from the frontal leading edge, where elevated Thorpe-scale diffusivity exceeding 10−2 m2/s has been observed hydrographically. These patches may indicate stratified turbulence, including broken internal wave segments, interleaving interfaces, and overturns, which may correspond to wave breaking, frontal instability, and shear instability, respectively. Our findings challenge the recently questioned classical hypothesis that energy cascades directly from internal waves to isotropic turbulence, instead supporting the paradigm of a stratified turbulence stage.
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spelling doaj-art-bffb07460e7e4c0994e4d0ca845b81462025-08-20T03:10:16ZengNature Portfolionpj Climate and Atmospheric Science2397-37222025-05-018111310.1038/s41612-025-01069-xIntensifying stratified turbulence and mixing towards the oceanic submesoscale frontQunshu Tang0Jianmin Lin1Wen Xu2Zhiyou Jing3Vincent C. H. Tong4State Key Laboratory of Ocean Sensing & Ocean College, Zhejiang UniversityState Key Laboratory of Ocean Sensing & Ocean College, Zhejiang UniversityOcean Academy, Zhejiang UniversityState Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of SciencesDepartment of Geography and Environmental Sciences, Northumbria UniversityAbstract The role of submesoscale processes as the primary energy source for ocean turbulence remains controversial due to observational limitations. Seismic imaging captures multi-scale processes from mesoscale to finescale, allowing us to infer turbulence processes. This study identified hundreds of ~200-m-long high seismic reflection patches, primarily caused by vertical temperature changes, moving at 0.24 ± 0.13 m/s across the deep-reaching front of Bransfield Current, Antarctica. Patch distribution within the main current is uneven, increasing exponentially towards the frontal leading edge. Over 95% of the detected patches are concentrated within 10 km from the frontal leading edge, where elevated Thorpe-scale diffusivity exceeding 10−2 m2/s has been observed hydrographically. These patches may indicate stratified turbulence, including broken internal wave segments, interleaving interfaces, and overturns, which may correspond to wave breaking, frontal instability, and shear instability, respectively. Our findings challenge the recently questioned classical hypothesis that energy cascades directly from internal waves to isotropic turbulence, instead supporting the paradigm of a stratified turbulence stage.https://doi.org/10.1038/s41612-025-01069-x
spellingShingle Qunshu Tang
Jianmin Lin
Wen Xu
Zhiyou Jing
Vincent C. H. Tong
Intensifying stratified turbulence and mixing towards the oceanic submesoscale front
npj Climate and Atmospheric Science
title Intensifying stratified turbulence and mixing towards the oceanic submesoscale front
title_full Intensifying stratified turbulence and mixing towards the oceanic submesoscale front
title_fullStr Intensifying stratified turbulence and mixing towards the oceanic submesoscale front
title_full_unstemmed Intensifying stratified turbulence and mixing towards the oceanic submesoscale front
title_short Intensifying stratified turbulence and mixing towards the oceanic submesoscale front
title_sort intensifying stratified turbulence and mixing towards the oceanic submesoscale front
url https://doi.org/10.1038/s41612-025-01069-x
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AT zhiyoujing intensifyingstratifiedturbulenceandmixingtowardstheoceanicsubmesoscalefront
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