Control of baroclinic instability by submesoscale topography

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Authors
Radko, Timour
Subjects
ocean processes
baroclinic flows
Advisors
Date of Issue
2020
Date
Publisher
Cambridge University Press
Language
Abstract
This study explores the control of mesoscale variability by topographic features with lateral scales that are less than the scale of the eddies generated by baroclinic instability. These dynamics are described using a combination of numerical simulations and an asymptotic multiscale model. The multiscale method makes it possible to express the system dynamics by a closed set of equations written entirely in terms of mesoscale variables, thereby providing a physical basis for the development of submesoscale parameterization schemes. The submesoscale topography is shown to influence such fundamental properties of mesoscale variability as the meridional eddy-induced transport and eddy kinetic energy. It is argued that the adverse influence of submesoscale topography on baroclinic instability is ultimately caused by the homogenization tendency of potential vorticity in the bottom density layer. The multiscale model formally assumes a substantial separation between the scales of interacting flow components. However, the comparison of asymptotic solutions with their submesoscale-resolving numerical counterparts indicates that the multiscale method is remarkably accurate even when scale separation is virtually non-existent.
Type
Article
Description
The article of record as published may be found at http://dx.doi.org/10.1017/jfm.2019.826
Series/Report No
Department
Oceanography
Organization
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NPS Report Number
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Format
32 p.
Citation
Radko, Timour. "Control of baroclinic instability by submesoscale topography." Journal of Fluid Mechanics 882 (2020).
Distribution Statement
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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