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Temperature-Salinity Structure of the North Atlantic Circulation and Associated Heat and Freshwater Transports

Title: Temperature-Salinity Structure of the North Atlantic Circulation and Associated Heat and Freshwater Transports.
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Name(s): Xu, Xiaobiao, author
Rhines, Peter B., author
Chassignet, Eric P., author
Type of Resource: text
Genre: Text
Date Issued: 2016-11
Physical Form: computer
online resource
Extent: 1 online resource
Language(s): English
Abstract/Description: This study investigates the circulation structure and relative contribution of circulation components to the time-mean meridional heat and freshwater transports in the North Atlantic, using numerical results of a high-resolution ocean model that are shown to be in excellent agreement with the observations. The North Atlantic circulation can be separated into the large-scale Atlantic meridional overturning circulation (AMOC) that is diapycnal and the subtropical and subpolar gyres that largely flow along isopycnal surfaces but also include prominent gyre-scale diapycnal overturning in the Subtropical Mode Water and Labrador Sea Water. Integrals of the meridional volume transport as a function of potential temperature theta and salinity S yield streamfunctions with respect to theta and to S, and heat functions. These argue for a significant contribution to the heat transport by the southward circulation of North Atlantic Deep Water. At 26.5 degrees N, the isopycnic component of the subtropical gyre is colder and fresher in the northward-flowing western boundary currents than the southward return flows, and it carries heat southward and freshwater northward, opposite of that of the diapycnal component. When combined, the subtropical gyre contributes virtually zero to the heat transport and the AMOC is responsible for all the heat transport across this latitude. The subtropical gyre however significantly contributes to the freshwater transport, reducing the 0.5-Sv (1 Sv =10(6) m(3) s(-1)) southward AMOC freshwater transport by 0.13 Sv. In the subpolar North Atlantic near 58 degrees N, the diapycnal component of the circulation, or the transformation of warm saline upper Atlantic water into colder fresher deep waters, is responsible for essentially all of the heat and freshwater transports.
Identifier: FSU_libsubv1_wos_000386205900009 (IID), 10.1175/JCLI-D-15-0798.1 (DOI)
Keywords: 26.5-degrees-n, components, coordinate ocean model, deep-water, eddy-resolving simulations, exchanges, flux, meridional overturning circulation, thermohaline circulation, variability
Publication Note: The publisher’s version of record is available at http://www.dx.doi.org/10.1175/JCLI-D-15-0798.1
Persistent Link to This Record: http://purl.flvc.org/fsu/fd/FSU_libsubv1_wos_000386205900009
Owner Institution: FSU
Is Part Of: Journal of Climate.
0894-8755
Issue: iss. 21, vol. 29

Choose the citation style.
Xu, X., Rhines, P. B., & Chassignet, E. P. (2016). Temperature-Salinity Structure of the North Atlantic Circulation and Associated Heat and Freshwater Transports. Journal Of Climate. Retrieved from http://purl.flvc.org/fsu/fd/FSU_libsubv1_wos_000386205900009