Circulation characteristics in three eddy-permitting models of the North Atlantic

• Published in: Progress in Oceanography
• Main Authors: Willebrand, Jürgen, Barnier, Bernard, Böning, Claus, Dieterich, Christian, Killworth, Peter D., Le Provost, Christian, Jia, Yanli, Molines, Jean-Marc, New, Adrian L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2001
• Subjects: Greenland; North Atlantic
• Online Access: https://eprints.soton.ac.uk/271/; https://eprints.soton.ac.uk/271/1/NEW_overview.pdf

A systematic intercomparison of three realistic eddy-permitting models of the North Atlantic circulation has been performed. The models use different concepts for the discretization of the vertical coordinate, namely geopotential levels, isopycnal layers, terrain-following (sigma) coordinates, respectively. Although these models were integrated under nearly identical conditions, the resulting large-scale model circulations show substantial differences. The results demonstrate that the large-scale thermohaline circulation is very sensitive to the model representation of certain localised processes, in particular to the amount and water mass properties of the overflow across the Greenland-Scotland region, to the amount of mixing within a few hundred kilometers south of the sills, and to several other processes at small or sub-grid scales. The different behaviour of the three models can to a large extent be explained as a consequence of the different model representation of these processes.