Baroclinic ocean response to climate forcing regulates decadal variability of ice-shelf melting in the Amundsen Sea

Silvano, Alessandro, Holland, Paul R., Naughten, Kaitlin A., Dragomir, Oana, Dutrieux, Pierre, Jenkins, Adrian, Si, Yidongfang, Stewart, Andrew L., Peña Molino, Beatriz, Janzing, Gregor W., S. Dotto, Tiago and Naveira Garabato, Alberto C. (2022) Baroclinic ocean response to climate forcing regulates decadal variability of ice-shelf melting in the Amundsen Sea. Geophysical Research Letters, 49 (24). ISSN 0094-8276

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Abstract

Warm ocean waters drive rapid ice-shelf melting in the Amundsen Sea. The ocean heat transport toward the ice shelves is associated with the Amundsen Undercurrent, a near-bottom current that flows eastward along the shelf break and transports warm waters onto the continental shelf via troughs. Here we use a regional ice-ocean model to show that, on decadal time scales, the undercurrent's variability is baroclinic (depth-dependent). Decadal ocean surface cooling in the tropical Pacific results in cyclonic wind anomalies over the Amundsen Sea. These wind anomalies drive a westward perturbation of the shelf-break surface flow and an eastward anomaly (strengthening) of the undercurrent, leading to increased ice-shelf melting. This contrasts with shorter time scales, for which surface current and undercurrent covary, a barotropic (depth-independent) behavior previously assumed to apply at all time scales. This suggests that interior ocean processes mediate the decadal ice-shelf response in the Amundsen Sea to climate forcing.

Item Type: Article
Uncontrolled Keywords: sdg 13 - climate action,sdg 14 - life below water ,/dk/atira/pure/sustainabledevelopmentgoals/climate_action
Faculty \ School: Faculty of Science > School of Environmental Sciences
UEA Research Groups: Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences
Depositing User: LivePure Connector
Date Deposited: 16 Dec 2022 09:30
Last Modified: 30 Jan 2024 03:26
URI: https://ueaeprints.uea.ac.uk/id/eprint/90245
DOI: 10.1029/2022GL100646

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