The Shelf Circulation of the Bellingshausen Sea
Abstract
Over recent decades, the West Antarctic Ice Sheet has experienced rapid thinning of its floating ice shelves as well as grounding line retreat across its marine‐terminating glaciers. The transport of warm Modified Circumpolar Deep Water (MCDW) onto the continental shelf, extensively documented along the West Antarctic Peninsula (WAP), and in the Amundsen Sea, has been identified as the key process for inducing these changes. The Bellingshausen Sea sits between the Amundsen Sea and the northern part of the WAP, but its oceanic properties remain remarkably under‐studied compared to surrounding regions. Here, we present observations collected from a hydrographic survey of the Bellingshausen Sea continental shelf in austral summer 2019. Using a combination of ship‐based and glider‐based CTD and lowered ADCP observations, we show that submarine troughs provide topographically steered pathways for MCDW from the shelf break toward deep embayments and ultimately under floating ice shelves. Warm MCDW enters the continental shelf at the deepest part of the Belgica Trough and flows onshore along the eastern side of the trough. Modification of these shoreward‐flowing waters by glacial melt is estimated by calculating meltwater fractions using an optimal multiparameter analysis. Meltwater is found to be elevated at the western edge of both the Latady and Belgica troughs. Meltwater distributions, consistent with other diagnostics, suggest a recirculation in each trough with modified waters eventually flowing westward upon leaving the Belgica Trough. Our results show that the Bellingshausen Sea is a critical part of the larger West Antarctic circulation system, linking the WAP and the Amundsen Sea.
Additional Information
© 2021. American Geophysical Union. Issue Online: 05 May 2021; Version of Record online: 05 May 2021; Accepted manuscript online: 29 April 2021; Manuscript accepted: 23 April 2021; Manuscript revised: 21 April 2021; Manuscript received: 08 October 2020. The authors acknowledge essential contributions from the captain and crew of the R/V Nathaniel B. Palmer as well as the Antarctic Support Contract staff during NBP19‐01. This work was supported by the National Science Foundation. A. F. Thompson, X. Ruan, and M. M. Flexas were supported by NSF OPP‐1644172 and the David and Lucille Packard Foundation. L. M. Schulze Chretien, K. Speer, N. Swaim, R. Schubert, and C. LoBuglio were supported by NSF OPP‐1643679. R. Oelerich is supported by the COMPASS project from the European Research Council under the European Union's Horizon 2020 research and innovation program (grant agreement no 741120). We are grateful for comments from three reviewers that substantially improved this manuscript. Data Availability Statement: All data used in this study are available at https://data.nodc.noaa.gov/cgi-bin/iso?id=gov.noaa.nodc:0210639.Attached Files
Published - 2020JC016871__pub.pdf
Accepted Version - 2020JC016871_acc.pdf
Supplemental Material - 2020jc016871-sup-0001-supporting_information_si-s01.pdf
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Additional details
- Eprint ID
- 109004
- Resolver ID
- CaltechAUTHORS:20210507-095912338
- NSF
- OPP‐1644172
- David and Lucile Packard Foundation
- NSF
- OPP‐1643679
- European Research Council (ERC)
- 741120
- Created
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2021-05-07Created from EPrint's datestamp field
- Updated
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2021-11-01Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences