Abstract

Estimates of turbulent mixing in geophysical settings typically depend on the efficiency at which shear-driven turbulence mixes density across isopycnals. To date, however, no unifying parameterization of diapycnal mixing efficiency exists due to the variability of natural flows and also due to certain ambiguities that arise from descriptions based on a single parameter. Here we highlight important ambiguities of some common single-parameter schemes in the context of a multiparameter framework that considers the independent effects of shear, buoyancy, and viscosity. Parameterizations based on the gradient Richardson number (Ri), the turbulent Froude number (FrT), and the buoyancy Reynolds number (Reb) are considered. The diagnostic ability of these parameters is examined using published data from both direct numerical simulations and field observations. Key Points We highlight important ambiguities of some common single parameter schemes the findings will be useful for modeling geophysical flows ©2014. American Geophysical Union. All Rights Reserved.

Department(s)

Civil, Architectural and Environmental Engineering

Publication Status

Free Access

Comments

National Science Foundation, Grant N00014-12-1-0279

Keywords and Phrases

diapycnal mixing; geophysical flows; mixing efficiency; parameterizations; stably stratified turbulent flows

International Standard Serial Number (ISSN)

1944-8007; 0094-8276

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2025 Wiley; American Geophysical Union, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

16 Jul 2014

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