Cross-Frontal Water Exchange on Georges Bank: Some Results from an U.S. GLOBEC/Georges Bank Program Model Study

摘要

This paper reviews recent progress on modeling cross-frontal water exchange on Georges Bank undertaken as part of the U.S. Global Ecosystem Northwest Atlantic/Georges Bank Study (U.S. GLOBEC/Georges Bank Program). A simple conceptual model is described first, followed by a discussion of four physical mechanisms associated with (1) strong nonlinear interaction, (2) asymmetric tidal mixing, (3) varying wind forcing, and (4) chaotic mixing. Some critical issues in modeling studies of fronts are also addressed. A new unstructured grid, finite-volume coastal ocean ecosystem model is introduced. This model combines the best of the finite-difference method for the simplest discrete computational efficiency and the finite-element method for geometric flexibility. Because the finite-volume method discretizes the integral form of the governing equations, this approach provides a better representation for the conservation laws of mass and momentum are satisfied, which is particularly important in the frontal regions.