Implementation of a geometrically informed and energetically constrained mesoscale eddy parameterization in an ocean circulation model

The global stratification and circulation, and their sensitivities to changes in forcing, depend crucially on the representation of the mesoscale eddy field in a numerical ocean circulation model. Here, a geometrically informed and energetically constrained parameterization framework for mesoscale e...

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Main Authors: Mak, J, Maddison, J, Marshall, D, Munday, D
Format: Journal article
Published: American Meteorological Society 2018
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author Mak, J
Maddison, J
Marshall, D
Munday, D
author_facet Mak, J
Maddison, J
Marshall, D
Munday, D
author_sort Mak, J
collection OXFORD
description The global stratification and circulation, and their sensitivities to changes in forcing, depend crucially on the representation of the mesoscale eddy field in a numerical ocean circulation model. Here, a geometrically informed and energetically constrained parameterization framework for mesoscale eddies — termed GEOMETRIC — is proposed and implemented in three-dimensional channel and sector models. The GEOMETRIC framework closes eddy buoyancy fluxes according to the standard Gent–McWilliams scheme, but with the eddy transfer coefficient constrained by the depth-integrated eddy energy field, provided through a prognostic eddy energy budget evolving with the mean state. It is found that coarse resolution models employing GEOMETRIC display broad agreement in the sensitivity of the circumpolar transport, meridional overturning circulation and depth-integrated eddy energy pattern to surface wind stress as compared with analogous reference calculations at eddy permitting resolutions. Notably, eddy saturation — the insensitivity of the time-mean circumpolar transport to changes in wind forcing — is found in the coarse resolution sector model. In contrast, differences in the sensitivity of the depth-integrated eddy energy are found in model calculations in the channel experiments that vary the eddy energy dissipation, attributed to the simple prognostic eddy energy equation employed. Further improvements to the GEOMETRIC framework require a shift in focus from how to close for eddy buoyancy fluxes to the representation of eddy energetics.
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spelling oxford-uuid:aeec1649-702b-406d-aedb-75c9237a7e3c2022-03-27T03:46:04ZImplementation of a geometrically informed and energetically constrained mesoscale eddy parameterization in an ocean circulation modelJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:aeec1649-702b-406d-aedb-75c9237a7e3cSymplectic Elements at OxfordAmerican Meteorological Society2018Mak, JMaddison, JMarshall, DMunday, DThe global stratification and circulation, and their sensitivities to changes in forcing, depend crucially on the representation of the mesoscale eddy field in a numerical ocean circulation model. Here, a geometrically informed and energetically constrained parameterization framework for mesoscale eddies — termed GEOMETRIC — is proposed and implemented in three-dimensional channel and sector models. The GEOMETRIC framework closes eddy buoyancy fluxes according to the standard Gent–McWilliams scheme, but with the eddy transfer coefficient constrained by the depth-integrated eddy energy field, provided through a prognostic eddy energy budget evolving with the mean state. It is found that coarse resolution models employing GEOMETRIC display broad agreement in the sensitivity of the circumpolar transport, meridional overturning circulation and depth-integrated eddy energy pattern to surface wind stress as compared with analogous reference calculations at eddy permitting resolutions. Notably, eddy saturation — the insensitivity of the time-mean circumpolar transport to changes in wind forcing — is found in the coarse resolution sector model. In contrast, differences in the sensitivity of the depth-integrated eddy energy are found in model calculations in the channel experiments that vary the eddy energy dissipation, attributed to the simple prognostic eddy energy equation employed. Further improvements to the GEOMETRIC framework require a shift in focus from how to close for eddy buoyancy fluxes to the representation of eddy energetics.
spellingShingle Mak, J
Maddison, J
Marshall, D
Munday, D
Implementation of a geometrically informed and energetically constrained mesoscale eddy parameterization in an ocean circulation model
title Implementation of a geometrically informed and energetically constrained mesoscale eddy parameterization in an ocean circulation model
title_full Implementation of a geometrically informed and energetically constrained mesoscale eddy parameterization in an ocean circulation model
title_fullStr Implementation of a geometrically informed and energetically constrained mesoscale eddy parameterization in an ocean circulation model
title_full_unstemmed Implementation of a geometrically informed and energetically constrained mesoscale eddy parameterization in an ocean circulation model
title_short Implementation of a geometrically informed and energetically constrained mesoscale eddy parameterization in an ocean circulation model
title_sort implementation of a geometrically informed and energetically constrained mesoscale eddy parameterization in an ocean circulation model
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AT marshalld implementationofageometricallyinformedandenergeticallyconstrainedmesoscaleeddyparameterizationinanoceancirculationmodel
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