Turbulent Heat Fluxes in a Mediterranean Eddy Quantified Using Seismic and Hydrographic Observations

Mediterranean eddies (meddies) play an essential role in transferring heat, salinity and momentum into the Atlantic Ocean. The rate of heat (and salt) flux from the meddy and its ultimate lifetime are key proxies to understanding how meddies impact the redistribution of heat and salt in the ocean sy...

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Main Authors: Wuxin Xiao, Zhou Meng
Format: Article
Language:English
Published: MDPI AG 2022-05-01
Series:Journal of Marine Science and Engineering
Subjects:
Online Access:https://www.mdpi.com/2077-1312/10/6/720
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author Wuxin Xiao
Zhou Meng
author_facet Wuxin Xiao
Zhou Meng
author_sort Wuxin Xiao
collection DOAJ
description Mediterranean eddies (meddies) play an essential role in transferring heat, salinity and momentum into the Atlantic Ocean. The rate of heat (and salt) flux from the meddy and its ultimate lifetime are key proxies to understanding how meddies impact the redistribution of heat and salt in the ocean system. A Mediterranean eddy was observed in the Gulf of Caidz in 2007 using seismic and hydrographic data. The spatial distribution of turbulent dissipation rates around the meddy is estimated from the seismically derived internal wave spectra subrange using fine-scale parameterization. Turbulent dissipated rates are lowest (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>11</mn></mrow></msup><mo> </mo><mi mathvariant="normal">W</mi><mo>/</mo><mi mathvariant="normal">k</mi><mi mathvariant="normal">g</mi></mrow></semantics></math></inline-formula>) within the core of the meddy but rise by nearly two orders of magnitude at the upper and lower boundaries, where signs of double diffusive convection are observed. Along the left flank of the meddy, thermohaline intrusions and interleaving of water masses are found in inverted temperature and salinity profiles, transporting heat laterally from the warm core to the Atlantic water with a flux of around <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>470</mn><mrow><mo> </mo><mi mathvariant="normal">W</mi></mrow><msup><mi mathvariant="normal">m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></semantics></math></inline-formula>. The meddy presented in this study is shown to decay in 2 years, primarily due to the heat loss associated with thermohaline intrusions. For the first time, heat fluxes around the meddy and its lifetime are quantified using seismic oceanography data, and the methods proposed here can be applied to more seismic datasets in the global oceans.
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spelling doaj.art-aba0323224de446393f3f4374cd585aa2023-11-23T17:21:48ZengMDPI AGJournal of Marine Science and Engineering2077-13122022-05-0110672010.3390/jmse10060720Turbulent Heat Fluxes in a Mediterranean Eddy Quantified Using Seismic and Hydrographic ObservationsWuxin Xiao0Zhou Meng1College of Meteorology and Oceanography, National University of Defense Technology, Changsha 410073, ChinaCollege of Meteorology and Oceanography, National University of Defense Technology, Changsha 410073, ChinaMediterranean eddies (meddies) play an essential role in transferring heat, salinity and momentum into the Atlantic Ocean. The rate of heat (and salt) flux from the meddy and its ultimate lifetime are key proxies to understanding how meddies impact the redistribution of heat and salt in the ocean system. A Mediterranean eddy was observed in the Gulf of Caidz in 2007 using seismic and hydrographic data. The spatial distribution of turbulent dissipation rates around the meddy is estimated from the seismically derived internal wave spectra subrange using fine-scale parameterization. Turbulent dissipated rates are lowest (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>11</mn></mrow></msup><mo> </mo><mi mathvariant="normal">W</mi><mo>/</mo><mi mathvariant="normal">k</mi><mi mathvariant="normal">g</mi></mrow></semantics></math></inline-formula>) within the core of the meddy but rise by nearly two orders of magnitude at the upper and lower boundaries, where signs of double diffusive convection are observed. Along the left flank of the meddy, thermohaline intrusions and interleaving of water masses are found in inverted temperature and salinity profiles, transporting heat laterally from the warm core to the Atlantic water with a flux of around <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>470</mn><mrow><mo> </mo><mi mathvariant="normal">W</mi></mrow><msup><mi mathvariant="normal">m</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></semantics></math></inline-formula>. The meddy presented in this study is shown to decay in 2 years, primarily due to the heat loss associated with thermohaline intrusions. For the first time, heat fluxes around the meddy and its lifetime are quantified using seismic oceanography data, and the methods proposed here can be applied to more seismic datasets in the global oceans.https://www.mdpi.com/2077-1312/10/6/720Mediterranean eddyheat fluxturbulent dissipationeddy lifetimeinternal waveseismic oceanography
spellingShingle Wuxin Xiao
Zhou Meng
Turbulent Heat Fluxes in a Mediterranean Eddy Quantified Using Seismic and Hydrographic Observations
Journal of Marine Science and Engineering
Mediterranean eddy
heat flux
turbulent dissipation
eddy lifetime
internal wave
seismic oceanography
title Turbulent Heat Fluxes in a Mediterranean Eddy Quantified Using Seismic and Hydrographic Observations
title_full Turbulent Heat Fluxes in a Mediterranean Eddy Quantified Using Seismic and Hydrographic Observations
title_fullStr Turbulent Heat Fluxes in a Mediterranean Eddy Quantified Using Seismic and Hydrographic Observations
title_full_unstemmed Turbulent Heat Fluxes in a Mediterranean Eddy Quantified Using Seismic and Hydrographic Observations
title_short Turbulent Heat Fluxes in a Mediterranean Eddy Quantified Using Seismic and Hydrographic Observations
title_sort turbulent heat fluxes in a mediterranean eddy quantified using seismic and hydrographic observations
topic Mediterranean eddy
heat flux
turbulent dissipation
eddy lifetime
internal wave
seismic oceanography
url https://www.mdpi.com/2077-1312/10/6/720
work_keys_str_mv AT wuxinxiao turbulentheatfluxesinamediterraneaneddyquantifiedusingseismicandhydrographicobservations
AT zhoumeng turbulentheatfluxesinamediterraneaneddyquantifiedusingseismicandhydrographicobservations