Abstract

Most commonly used models for turbulent mixing in the ocean rely on a background stratification against which turbulence must work to stir the fluid. While this background stratification is typically well defined in idealized numerical models, it is more difficult to capture in observations. Here, a potential discrepancy in ocean mixing estimates due to the chosen calculation of the background stratification is explored using direct numerical simulation data of breaking internal waves on slopes. Two different methods for computing the buoyancy frequency, one based on a three-dimensionally sorted density field (often used in numerical models) and the other based on locally sorted vertical density profiles (often used in the field), are used to quantify the effect of on turbulence quantities. It is shown that how is calculated changes not only the flux Richardson number, which is often used to parameterize turbulent mixing, but also the turbulence activity number or the Gibson number, leading to potential errors in estimates of the mixing efficiency using -based parameterizations.

Department(s)

Civil, Architectural and Environmental Engineering

Comments

National Science Foundation, Grant 1151838

Keywords and Phrases

internal waves; stratified turbulence; turbulent mixing

International Standard Serial Number (ISSN)

1469-7645; 0022-1120

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2025 Cambridge University Press, All rights reserved.

Publication Date

25 Nov 2017

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