Numerical simulations of melt-driven double-diffusive fluxes in a turbulent boundary layer beneath an ice shelf

Middleton, Leo ORCID: https://orcid.org/0000-0002-2821-6992; Vreugdenhil, Catherine A.; Holland, Paul R. ORCID: https://orcid.org/0000-0001-8370-289X; Taylor, John R.. 2021 Numerical simulations of melt-driven double-diffusive fluxes in a turbulent boundary layer beneath an ice shelf. Journal of Physical Oceanography, 51 (2). 403-418. https://doi.org/10.1175/JPO-D-20-0114.1

Before downloading, please read NORA policies.

Preview

Text © Copyright 2021 American Meteorological Society (AMS). For permission to reuse any portion of this Work, please contact permissions@ametsoc.org. Any use of material in this Work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC § 108) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. All AMS journals and monograph publications are registered with the Copyright Clearance Center (https://www.copyright.com). Additional details are provided in the AMS Copyright Policy statement, available on the AMS website (https://www.ametsoc.org/PUBSCopyrightPolicy). phoc-jpo-d-20-0114.1.pdf - Published Version Download (2MB) | Preview

Text © Copyright 2021 American Meteorological Society (AMS). MiddletonEtAl2020.pdf - Accepted Version Restricted to NORA staff only Download (6MB) | Request a copy

Abstract/Summary

The transport of heat and salt through turbulent ice shelf-ocean boundary layers is a large source of uncertainty within ocean models of ice shelf cavities. This study uses small-scale, high resolution, 3D numerical simulations to model an idealised boundary layer beneath a melting ice shelf to investigate the influence of ambient turbulence on double-diffusive convection (i.e. convection driven by the difference in diffusivities between salinity and temperature). Isotropic turbulence is forced throughout the simulations and the temperature and salinity are initialised with homogeneous values similar to observations. The initial temperature and the strength of forced turbulence are varied as controlling parameters within an oceanographically relevant parameter space. Two contrasting regimes are identified. In one regime double-diffusive convection dominates, and in the other convection is inhibited by the forced turbulence. The convective regime occurs for high temperatures and low turbulence levels, where it is long-lived and affects the flow, melt rate and melt pattern. A criterion for identifying convection in terms of the temperature and salinity profiles, and the turbulent dissipation rate, is proposed. This criterion may be applied to observations and theoretical models to quantify the effect of double-diffusive convection on ice shelf melt rates.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1175/JPO-D-20-0114.1
ISSN:	0022-3670
Additional Keywords:	Ice shelves; Mixing; Turbulence
Date made live:	07 Dec 2020 11:21 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/528968

Actions (login required)

View Item

Document Downloads

More statistics for this item...