A numerical scheme for modeling tidal wetting and drying

Abstract

This paper introduces a numerical scheme developed to model the wetting and drying of coastal areas by the tide, suitable for an oceanic circulation model using finite differences. It is based on existing numerical schemes developed for isopycnic models for which the layer thickness can vanish when they interact with the bottom topography. Some original features are added and the scheme is optimized to accurately reproduce analytical solutions of an idealized problem. The main parameters of this numerical scheme are (1) a critical height, which depends on the local bottom slope and the grid step, and (2) the Rossby number. This original numerical scheme is applied to a realistic barotropic configuration of the Normand-Breton Gulf where tidal amplitudes are large and where the wet/dry front location varies greatly. Copyright 2011 by the American Geophysical Union.