Asymmetry of Submesoscale Instabilities in Anticyclonic and Cyclonic Eddies

Abstract The upper‐ocean relative vorticity has been found to be cyclonically skewed, but altimetry observations indicate that long‐lifespan mesoscale eddies tend to be anticyclonic. We are thus interested in whether cyclonic or anticyclonic eddies are more unstable under similar circumstances. Here...

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Main Authors: Weian Shi, Hongyang Lin, Qiang Deng, Jianyu Hu
Format: Article
Language:English
Published: Wiley 2024-01-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1029/2023GL106853
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author Weian Shi
Hongyang Lin
Qiang Deng
Jianyu Hu
author_facet Weian Shi
Hongyang Lin
Qiang Deng
Jianyu Hu
author_sort Weian Shi
collection DOAJ
description Abstract The upper‐ocean relative vorticity has been found to be cyclonically skewed, but altimetry observations indicate that long‐lifespan mesoscale eddies tend to be anticyclonic. We are thus interested in whether cyclonic or anticyclonic eddies are more unstable under similar circumstances. Here we use submesoscale‐resolving simulations of idealized mesoscale eddies, incorporating theoretical analyses, to investigate asymmetries of submesoscale instabilities within the anticyclones and cyclones. It is found that submesoscale filaments initiate at regions with the largest horizontal buoyancy gradients for both anticyclones and cyclones, but these filaments subsequently rotate outward in anticyclones while inward in cyclones. Hence submesoscales are more vigorous at anticyclone peripheries and the cyclone center. Such differing distributions and evolutions of submesoscale processes are primarily caused by changes in the background stratification associated with the decaying of mesoscale eddies. The active submesoscales near the cyclone center eventually distort its core structure radically, whereas the anticyclone remains largely unaffected.
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spelling doaj-art-28ec17d012c14f3e851fd2cc3b3a16072025-08-20T03:52:32ZengWileyGeophysical Research Letters0094-82761944-80072024-01-01512n/an/a10.1029/2023GL106853Asymmetry of Submesoscale Instabilities in Anticyclonic and Cyclonic EddiesWeian Shi0Hongyang Lin1Qiang Deng2Jianyu Hu3State Key Laboratory of Marine Environmental Science Department of Physical Oceanography College of Ocean and Earth Sciences Xiamen University Xiamen ChinaState Key Laboratory of Marine Environmental Science Department of Physical Oceanography College of Ocean and Earth Sciences Xiamen University Xiamen ChinaState Key Laboratory of Marine Environmental Science Department of Physical Oceanography College of Ocean and Earth Sciences Xiamen University Xiamen ChinaState Key Laboratory of Marine Environmental Science Department of Physical Oceanography College of Ocean and Earth Sciences Xiamen University Xiamen ChinaAbstract The upper‐ocean relative vorticity has been found to be cyclonically skewed, but altimetry observations indicate that long‐lifespan mesoscale eddies tend to be anticyclonic. We are thus interested in whether cyclonic or anticyclonic eddies are more unstable under similar circumstances. Here we use submesoscale‐resolving simulations of idealized mesoscale eddies, incorporating theoretical analyses, to investigate asymmetries of submesoscale instabilities within the anticyclones and cyclones. It is found that submesoscale filaments initiate at regions with the largest horizontal buoyancy gradients for both anticyclones and cyclones, but these filaments subsequently rotate outward in anticyclones while inward in cyclones. Hence submesoscales are more vigorous at anticyclone peripheries and the cyclone center. Such differing distributions and evolutions of submesoscale processes are primarily caused by changes in the background stratification associated with the decaying of mesoscale eddies. The active submesoscales near the cyclone center eventually distort its core structure radically, whereas the anticyclone remains largely unaffected.https://doi.org/10.1029/2023GL106853submesoscale instabilitiesasymmetrymesoscale eddies
spellingShingle Weian Shi
Hongyang Lin
Qiang Deng
Jianyu Hu
Asymmetry of Submesoscale Instabilities in Anticyclonic and Cyclonic Eddies
Geophysical Research Letters
submesoscale instabilities
asymmetry
mesoscale eddies
title Asymmetry of Submesoscale Instabilities in Anticyclonic and Cyclonic Eddies
title_full Asymmetry of Submesoscale Instabilities in Anticyclonic and Cyclonic Eddies
title_fullStr Asymmetry of Submesoscale Instabilities in Anticyclonic and Cyclonic Eddies
title_full_unstemmed Asymmetry of Submesoscale Instabilities in Anticyclonic and Cyclonic Eddies
title_short Asymmetry of Submesoscale Instabilities in Anticyclonic and Cyclonic Eddies
title_sort asymmetry of submesoscale instabilities in anticyclonic and cyclonic eddies
topic submesoscale instabilities
asymmetry
mesoscale eddies
url https://doi.org/10.1029/2023GL106853
work_keys_str_mv AT weianshi asymmetryofsubmesoscaleinstabilitiesinanticyclonicandcycloniceddies
AT hongyanglin asymmetryofsubmesoscaleinstabilitiesinanticyclonicandcycloniceddies
AT qiangdeng asymmetryofsubmesoscaleinstabilitiesinanticyclonicandcycloniceddies
AT jianyuhu asymmetryofsubmesoscaleinstabilitiesinanticyclonicandcycloniceddies