Some Implications of Ekman Layer Dynamics for Cross-Shelf Exchange in the Amundsen Sea

• DOI: 10.1175/jpo-d-11-041.1
• Publication Date: 2012-03-08T21:56:44Z
• Authors: A. K. Wåhlin; R. D. Muench; L. Arneborg; G. Björk; H. K. Ha; S. H. Lee; H. Alsén
• Keywords: Ekman layer; Ekman transport; Seabed; Circumpolar deep water; Boundary current; Antarctic Bottom Water

Abstract The exchange of warm, salty seawater across the continental shelves off West Antarctica leads to subsurface glacial melting at interface between ocean and Antarctic Ice Sheet. One mechanism that contributes cross-shelf transport is Ekman induced by along-slope currents over slope shelf break. An investigation this process applied Amundsen Sea shelfbreak region, using recently acquired historical field data guide analyses. Along-slope were observed transects eastern western reaches slope. Currents in east flowed eastward, farther west westward. Under eastward-flowing currents, hydrographic isolines sloped upward paralleling seabed. In layer, declining buoyancy forces rather than friction bringing velocity zero basin water part was dominated originating from 800–1000-m depth shelf, suggesting such frequently occurs. authors show arrested layers can supply deep break section, where it has access shelf. Because no unmodified off-shelf found on part, bottom layer does not appear a likely for delivery warm area. Warming most pronounced deep-water temperature increased 0.6°C during past decade.