Effect of the overflows on the circulation in the Subpolar North Atlantic: A regional model study

Redler, Rene and Böning, Claus W. (1997) Effect of the overflows on the circulation in the Subpolar North Atlantic: A regional model study Journal of Geophysical Research: Oceans, 102 (C8) . pp. 18529-18552. DOI 10.1029/97JC00021.

[img]
Preview
Text
jgrc6954.pdf - Published Version
Available under License ["licenses_description_cc_by_4.0" not defined].

Download (3404Kb) | Preview

Supplementary data:

Abstract

An ocean circulation model for process studies of the Subpolar North Atlantic is developed based on the Geophysical Fluid Dynamics Laboratory (GFDL) Modular Ocean Model (MOM) code. The basic model configuration is identical with that of the high-resolution model (with a grid size of 1/3° × 2/5°) of the World Ocean Circulation Experiment (WOCE) Community Modeling Effort (CME), except that the domain of integration is confined to the area from 43° to 65°N. Open boundary conditions are used for the inflows and outflows across the northern and southern boundaries. A comparison with the CME model covering the whole North Atlantic (from 15°S to 65°N) shows that the regional model, with inflow conditions at 43°N from a CME solution, is able to reproduce the CME results for the subpolar area. Thus the potential of a regional model lies in its use as an efficient tool for numerical experiments aiming at an identification of the key physical processes that determine the circulation and water mass transformations in the subpolar gyre. This study deals primarily with the representation and role of the overflow waters that enter the domain at the northern boundary. Sensitivity experiments show the effect of closed versus open boundaries, of different hydrographic conditions at inflow points, and of the representation of the narrow Faeroe Bank Channel. The representation of overflow processes in the Denmark Strait is the main controlling mechanism for the net transport of the deep boundary current along the Greenland continental slope and further downstream. Changes in the Faeroe Bank Channel throughflow conditions have a comparatively smaller effect on the deep transport in the western basin but strongly affect the water mass characteristics in the eastern North Atlantic. The deep water transport at Cape Farewell and further downstream is enhanced compared to the combined Denmark Strait and Iceland-Scotland overflows. This enhancement can be attributed to a barotropic recirculation in the Irminger Basin which is very sensitive to the outflow conditions in the Denmark Strait. The representation of both overflow regions determine the upper layer circulation in the Irminger and Iceland Basins, in particular the path of the North Atlantic Current.

Document Type: Article
Keywords: Analytical Modeling and Laboratory Experiments; Atlantic Ocean; Currents; Numerical Modelin
Research affiliation: OceanRep > Leibniz Institute of Marine Sciences
AWI
Refereed: Yes
DOI etc.: 10.1029/97JC00021
ISSN: 2169-9275
Date Deposited: 06 Oct 2008 14:35
Last Modified: 24 Nov 2017 12:03
URI: http://eprints.uni-kiel.de/id/eprint/6400

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...