Pathways of inter-basin exchange from the Bellingshausen Sea to the Amundsen Sea

Flexas, M. Mar, Thompson, Andrew F., Robertson, Megan L., Speer, Kevin, Sheehan, Peter M. F. ORCID: https://orcid.org/0000-0002-4906-5724 and Heywood, Karen J. ORCID: https://orcid.org/0000-0001-9859-0026 (2024) Pathways of inter-basin exchange from the Bellingshausen Sea to the Amundsen Sea. JGR Oceans, 129 (6). ISSN 2169-9275

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Abstract

The West Antarctic Ice Sheet is experiencing rapid thinning of its floating ice shelves, largely attributed to oceanic basal melt. Numerical models suggest that the Bellingshausen Sea has a key role in setting water properties in the Amundsen Sea and further downstream. Yet, observations confirming these pathways of volume and tracer exchange between coast and shelf break and their impact on inter-sea exchange remain sparse. Here we analyze the circulation and distribution of glacial meltwater at the boundary between the Bellingshausen Sea and the Amundsen Sea using a combination of glider observations from January 2020 and hydrographic data from instrumented seals. Meltwater distributions over previously unmapped western regions of the continental shelf and slope reveal two distinct meltwater cores with different optical backscatter properties. At Belgica Trough, a subsurface meltwater peak is linked with hydrographic properties from Venable Ice Shelf. West of Belgica Trough, the vertical structure of meltwater concentration changes, with peak values occurring at greater depths and denser isopycnals. Hydrographic analysis suggests that the western (deep) meltwater core is supplied from the eastern part of Abbot Ice Shelf, and is exported to the shelf break via a previously-overlooked bathymetric trough (here named Seal Trough). Hydrographic sections constructed from seal data reveal that the Antarctic Coastal Current extends west past Belgica Trough, delivering meltwater to the Amundsen Sea. Each of these circulation elements has distinct dynamical implications for the evolution of ice shelves and water masses both locally and downstream, in the Amundsen Sea and beyond.

Item Type: Article
Additional Information: Funding Information: This work was funded by National Science Foundation Grants OPP\u20101644172 (M.M.F., A.F.T. and M.L.R.), OPP\u20101643679 (K.S.), and OCE\u20101658479 (K.S.); National Aeronautics and Space Administration Grant 80NSSC21K0916 (M.M.F. and A.F.T.); and the Internal Research and Technology Development program (Earth 2050 project), Jet Propulsion Laboratory, California Institute of Technology (M.M.F. and A.F.T.). This research has received funding to the COMPASS project from the European Research Council under the European Union's Horizon 2020 research and innovation programme (Grant agreement n\u00B0 741120). We thank glider pilots from the University of East Anglia and from the California Institute of Technology for their help piloting SG621 (a.k.a. Moby) during the TABASCO cruise. Special thanks to Gillian Damerell for her help with the glider processing toolbox and to Michael Schodlok for providing the IBCSO\u2010BedMachine blended bathymetry file. We thank our colleagues Ryan Schubert, Lena Schulze Cretien and Ruth Moorman for helpful conversations. We thank two anonymous reviewers for their time and valuable comments that helped improve this manuscript. Funding Information: This work was funded by National Science Foundation Grants OPP-1644172 (M.M.F., A.F.T. and M.L.R.), OPP-1643679 (K.S.), and OCE-1658479 (K.S.); National Aeronautics and Space Administration Grant 80NSSC21K0916 (M.M.F. and A.F.T.); and the Internal Research and Technology Development program (Earth 2050 project), Jet Propulsion Laboratory, California Institute of Technology (M.M.F. and A.F.T.). This research has received funding to the COMPASS project from the European Research Council under the European Union's Horizon 2020 research and innovation programme (Grant agreement n\u00B0 741120). We thank glider pilots from the University of East Anglia and from the California Institute of Technology for their help piloting SG621 (a.k.a. Moby) during the TABASCO cruise. Special thanks to Gillian Damerell for her help with the glider processing toolbox and to Michael Schodlok for providing the IBCSO-BedMachine blended bathymetry file. We thank our colleagues Ryan Schubert, Lena Schulze Cretien and Ruth Moorman for helpful conversations. We thank two anonymous reviewers for their time and valuable comments that helped improve this manuscript. Publisher Copyright: © 2024. American Geophysical Union. All Rights Reserved.
Uncontrolled Keywords: bellingshausen sea,glider data,ice-ocean interactions,in situ observations,pathways,seal data,oceanography,geophysics,geochemistry and petrology,space and planetary science,earth and planetary sciences (miscellaneous) ,/dk/atira/pure/subjectarea/asjc/1900/1910
Faculty \ School: Faculty of Science > School of Environmental Sciences
University of East Anglia Research Groups/Centres > Theme - ClimateUEA
UEA Research Groups: Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 03 Jun 2024 14:30
Last Modified: 17 Jun 2024 08:30
URI: https://ueaeprints.uea.ac.uk/id/eprint/95378
DOI: 10.1029/2023JC020080

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