Significant sink of ocean-eddy energy near western boundaries

Ocean eddies generated through instability of the mean flow are a vital component of the energy budget of the global ocean1-3. In equilibrium, the sources and sinks of eddy energy have to be balanced. However, where and how eddy energy is removed remains uncertain3,4. Ocean eddies are observed to pr...

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Main Authors: Zhai, X, Johnson, H, Marshall, D
Format: Journal article
Language:English
Published: 2010
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author Zhai, X
Johnson, H
Marshall, D
author_facet Zhai, X
Johnson, H
Marshall, D
author_sort Zhai, X
collection OXFORD
description Ocean eddies generated through instability of the mean flow are a vital component of the energy budget of the global ocean1-3. In equilibrium, the sources and sinks of eddy energy have to be balanced. However, where and how eddy energy is removed remains uncertain3,4. Ocean eddies are observed to propagate westwards at speeds similar to the phase speeds of classical Rossby waves5, but what happens to the eddies when they encounter the western boundary is unclear. Here we use a simple reduced-gravity model along with satellite altimetry data to show that the western boundary acts as a "graveyardg" for the westward-propagating ocean eddies. We estimate a convergence of eddy energy near the western boundary of approximately 0.1-0.3 TW, poleward of 10°in latitude. This energy is most probably scattered into high-wavenumber vertical modes, resulting in energy dissipation and diapycnal mixing. If confirmed, this eddy-energy sink will have important implications for the ocean circulation. © 2010 Macmillan Publishers Limited. All rights reserved.
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spelling oxford-uuid:20c28ed0-7cd4-48e8-8aa4-342f6c6dbedb2022-03-26T11:29:19ZSignificant sink of ocean-eddy energy near western boundariesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:20c28ed0-7cd4-48e8-8aa4-342f6c6dbedbEnglishSymplectic Elements at Oxford2010Zhai, XJohnson, HMarshall, DOcean eddies generated through instability of the mean flow are a vital component of the energy budget of the global ocean1-3. In equilibrium, the sources and sinks of eddy energy have to be balanced. However, where and how eddy energy is removed remains uncertain3,4. Ocean eddies are observed to propagate westwards at speeds similar to the phase speeds of classical Rossby waves5, but what happens to the eddies when they encounter the western boundary is unclear. Here we use a simple reduced-gravity model along with satellite altimetry data to show that the western boundary acts as a "graveyardg" for the westward-propagating ocean eddies. We estimate a convergence of eddy energy near the western boundary of approximately 0.1-0.3 TW, poleward of 10°in latitude. This energy is most probably scattered into high-wavenumber vertical modes, resulting in energy dissipation and diapycnal mixing. If confirmed, this eddy-energy sink will have important implications for the ocean circulation. © 2010 Macmillan Publishers Limited. All rights reserved.
spellingShingle Zhai, X
Johnson, H
Marshall, D
Significant sink of ocean-eddy energy near western boundaries
title Significant sink of ocean-eddy energy near western boundaries
title_full Significant sink of ocean-eddy energy near western boundaries
title_fullStr Significant sink of ocean-eddy energy near western boundaries
title_full_unstemmed Significant sink of ocean-eddy energy near western boundaries
title_short Significant sink of ocean-eddy energy near western boundaries
title_sort significant sink of ocean eddy energy near western boundaries
work_keys_str_mv AT zhaix significantsinkofoceaneddyenergynearwesternboundaries
AT johnsonh significantsinkofoceaneddyenergynearwesternboundaries
AT marshalld significantsinkofoceaneddyenergynearwesternboundaries