Heterogeneous mixing processes observed in the Dotson Ice Shelf Outflow, Antarctica

Dotto, Tiago S., Sheehan, Peter M. F., Zheng, Yixi, Hall, Rob A., Damerell, Gillian M. and Heywood, Karen J. (2025) Heterogeneous mixing processes observed in the Dotson Ice Shelf Outflow, Antarctica. Journal of Geophysical Research: Oceans, 130 (5). ISSN 2169-9275

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Abstract

We present the first observations of ocean turbulent mixing rate in front of the Dotson Ice Shelf, where meltwater-enriched water leaves the cavity. The observations showed elevated turbulent kinetic energy dissipation rates (ε; ∼10−7 W kg−1) and turbulent diapycnal diffusivities (κ; ∼10−2 m2 s−1) near the seabed and in middepth layers, which are three orders of magnitude above background values away from the outflow. Elevated diapycnal fluxes of heat and salt were observed in regions of high mixing, moving vertically on average O ∼ 10 W m−2 and O ∼ 10−6 kg m−2 s−1, respectively, toward shallow depths. At middepth layers, the overturning instabilities are characterized by shear-driven symmetric and centrifugal instabilities. Our observations provide an understanding of mixing in front of fast-melting ice shelves and are key to developing better parameterizations and representations of mixing in climate models.

Item Type:	Article
Additional Information:	Data Availability Statement: BedMachine Antarctic v3 is available in Morlighem (2022). CATS2008 is available at https://www.esr.org/research/polar-tide-models/list-of-polar-tide-models/cats2008/. The CTD data set is available in NSF/NERC ARTEMIS and ITGC TARSAN (2024). SADCP data set is available in Wellner (2022). VMP data set is available in Dotto et al. (2024). TEOS-10 and Pre-TEOS10 software are available at https://www.teos-10.org/index.htm. Funding information: This work is from the Thwaites-Amundsen Regional Survey and Network Integrating Atmosphere-Ice-Ocean Processes (TARSAN) project, a component of the International Thwaites Glacier Collaboration (ITGC; https://thwaitesglacier.org/). TSD, KJH, and RAH were supported by TARSAN project Grant NE/S006419/1. TSD was supported by U.K. Natural Environment Research Council National Capability Program AtlantiS (NE/Y005589/1). KJH, RAH, and YZ were supported by ARTEMIS project (NE/W007045/1). KJH, PMFS and YZ were supported by the COMPASS project (Grant 741120), which was funded by the European Research Council under the Horizon 2020 program. GMD was supported by the COMPASS project and the European Union's Horizon 2020 Research and Innovation Program under the Marie Skłodowska-Curie grant agreement No 101034309.
Faculty \ School:	Faculty of Science > School of Environmental Sciences Faculty of Science University of East Anglia Research Groups/Centres > Theme - ClimateUEA
UEA Research Groups:	Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences Faculty of Science > Research Groups > Collaborative Centre for Sustainable Use of the Seas
Related URLs:	https://agupubs.onlinelibrary.wiley.com/...
Depositing User:	LivePure Connector
Date Deposited:	19 May 2025 11:30
Last Modified:	20 May 2025 00:11
URI:	https://ueaeprints.uea.ac.uk/id/eprint/99293
DOI:	10.1029/2024JC022051

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