Seasonal overturning circulation in the Red Sea: 1. Model validation and summer circulation

TitleSeasonal overturning circulation in the Red Sea: 1. Model validation and summer circulation
Publication TypeJournal Article
Year of Publication2014
AuthorsYao F.C, Hoteit I., Pratt L.J, Bower A.S, Zhai P., Kohl A., Gopalakrishnan G
JournalJournal of Geophysical Research-Oceans
Volume119
Pagination2238-2262
Date Published2014/04
Type of ArticleArticle
ISBN Number2169-9275
Accession NumberWOS:000336213200008
Keywordsal mandab; bab-el-mandab; deep-water; dynamics; exchange flow; general-circulation; indian-ocean; intermediate; MITgcm; overturning; Red Sea; strait; variability
Abstract

The overturning circulation in the Red Sea exhibits a distinct seasonally reversing pattern and is studied using high-resolution MIT general circulation model simulations. In the first part of this study, the vertical and horizontal structure of the summer overturning circulation and its dynamical mechanisms are presented from the model results. The seasonal water exchange in the Strait of Bab el Mandeb is successfully simulated, and the structures of the intruding subsurface Gulf of Aden intermediate water are in good agreement with summer observations in 2011. The model results suggest that the summer overturning circulation is driven by the combined effect of the shoaling of the thermocline in the Gulf of Aden resulting from remote winds in the Arabian Sea and an upward surface slope from the Red Sea to the Gulf of Aden set up by local surface winds in the Red Sea. In addition, during late summer two processes associated, respectively, with latitudinally differential heating and increased salinity in the southern Red Sea act together to cause the reversal of the contrast of the vertical density structure and the cessation of the summer overturning circulation. Dynamically, the subsurface northward pressure gradient force is mainly balanced by vertical viscosity resulting from the vertical shear and boundary friction in the Strait of Bab el Mandeb. Unlike some previous studies, the three-layer summer exchange flows in the Strait of Bab el Mandeb do not appear to be hydraulically controlled. Key Points Overturning circulation in the Red Sea is successfully simulated with MITgcm During summer, the GAIW enters the Red Sea as an eastern boundary current Remote and local winds and latitudinally differential heating control intrusion

DOI10.1002/2013jc009004
Short TitleJ Geophys Res-Oceans
Integrated Research Themes: 
Student Publication: 
No