Circulation and meltwater distribution in the Bellingshausen Sea: From shelf break to coast

• Published in: Geophysical Research Letters
• Main Authors: Zhang, Xiyue, Thompson, Andrew F., Flexas, Mar M., Roquet, Fabien, Bornemann, Horst
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2016
• Subjects: Bellingshausen Sea; Circumpolar Deep Water; slope current; animal-borne sampling; Alfred Wegener Institute; Antarc*; Antarctic; Ice Sheet; Ice Shelf; Ice Shelves
• Online Access: https://doi.org/10.1002/2016GL068998

West Antarctic ice shelves have thinned dramatically over recent decades. Oceanographic measurements that explore connections between offshore warming and transport across a continental shelf with variable bathymetry toward ice shelves are needed to constrain future changes in melt rates. Six years of seal-acquired observations provide extensive hydrographic coverage in the Bellingshausen Sea, where ship-based measurements are scarce. Warm but modified Circumpolar Deep Water floods the shelf and establishes a cyclonic circulation within the Belgica Trough with flow extending toward the coast along the eastern boundaries and returning to the shelf break along western boundaries. These boundary currents are the primary water mass pathways that carry heat toward the coast and advect ice shelf meltwater offshore. The modified Circumpolar Deep Water and meltwater mixtures shoal and thin as they approach the continental slope before flowing westward at the shelf break, suggesting the presence of the Antarctic Slope Current. Constraining meltwater pathways is a key step in monitoring the stability of the West Antarctic Ice Sheet. © 2016 American Geophysical Union. Received 4 APR 2016; Accepted 27 MAY 2016; Accepted article online 1 JUN 2016; Published online 20 JUN 2016. The MEOP consortium coordinates several seal-tagging national programs to provide a comprehensive oceanographic coverage in Polar Regions (http://www.meop.net/). Bellingshausen Sea data were produced with support from the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (GER), the Instituto Antártico Argentino (ARG), the National Oceanographic Partnership Program (USA), and the Brazilian National Research Council (BRA). Data and information can be accessed at www.coriolis.eu.org with details in the supporting information. We would like to thank the anonymous reviewers for their constructive comments. A.F.T. acknowledges support by NSF award OPP-1246460. M.M.F. is supported by the NASA Postdoctoral Program administered by Oak ...