Seasonal overturning circulation in the Red Sea: 2. Winter circulation

TitleSeasonal overturning circulation in the Red Sea: 2. Winter circulation
Publication TypeJournal Article
Year of Publication2014
AuthorsYao F.C, Hoteit I., Pratt L.J, Bower A.S, Kohl A., Gopalakrishnan G, Rivas D.
JournalJournal of Geophysical Research-Oceans
Volume119
Pagination2263-2289
Date Published2014/04
Type of ArticleArticle
ISBN Number2169-9275
Accession NumberWOS:000336213200009
Keywordsboundary; currents; deep-water; exchange; general-circulation; mandab; marginal seas; MITgcm; overturning; Red Sea; thermohaline circulation
Abstract

The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented by 1980, and the climatological mean are analyzed using model output to delineate the three-dimensional structure and to investigate the underlying dynamical mechanisms. The horizontal model circulation in the winter of 1980 is dominated by energetic eddies. The climatological model mean results suggest that the surface inflow intensifies in a western boundary current in the southern Red Sea that switches to an eastern boundary current north of 24 degrees N. The overturning is accomplished through a cyclonic recirculation and a cross-basin overturning circulation in the northern Red Sea, with major sinking occurring along a narrow band of width about 20 km along the eastern boundary and weaker upwelling along the western boundary. The northward pressure gradient force, strong vertical mixing, and horizontal mixing near the boundary are the essential dynamical components in the model's winter overturning circulation. The simulated water exchange is not hydraulically controlled in the Strait of Bab el Mandeb; instead, the exchange is limited by bottom and lateral boundary friction and, to a lesser extent, by interfacial friction due to the vertical viscosity at the interface between the inflow and the outflow. Key Points Sinking occurs in a narrow boundary layer along the eastern boundary Surface western boundary current switches into an eastern boundary current Water exchange in the Strait of Bab el Mandeb is not hydraulically controlled

DOI10.1002/2013jc009331
Short TitleJ Geophys Res-Oceans
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