Representing the Global-Scale Water Masses in Ocean General Circulation Models

Abstract

Abstract A hierarchy of coarse-resolution World Ocean experiments were integrated with a view to determining the most appropriate representation of the global-scale water masses in ocean general circulation models. The largest-scale response of the simulated ocean to the prescribed forcing in each model run is described. The World Ocean model eventually has a realistic approximation of continental outlines and bottom bathymetry. The model forcing at the sea surface is derived from climatological fields of temperature, salinity, and wind stress. The first experiment begins with a quite unrealistic and idealized World Ocean. Subsequent experiments then employ more realistic surface boundary conditions, model geometry, and internal physical processes. In all, 16 changes to the model configuration are investigated. A fundamental dynamical constraint in the Drake Passage gap appears to limit the outflow rate of bottom water in the Antarctic region. This constraint acts to decouple the extreme Antarctic waters ...