REVIEW OF RECENT DEVELOPMENTS IN TIDAL HYDRODYNAMIC MODELING .1. SPECTRAL MODELS

In this paper we present a brief overview, with a comprehensive Set of references to recently published papers for detail, of a range of tec hniques used in tidal hydrodynamic modeling and recent progress in the field. Although the paper aims to introduce the topic to someone new to the area, the main emphasis is on new developments in near coastal (shallow sea) tidal modeling, and consequently we concentrate an three -dimensional modeling, which has progressed significantly in recent ye ars. The paper gives a brief account of methods used to discretize the hydrodynamic equations in the horizontal, namely finite difference, f inite element and boundary-fitted coordinates, and through time. The r epresentation of tidal current structure in a three-dimensional model using a spectral method in the vertical is also described. In this met hod the subgrid scale vertical diffusion of momentum, which has a majo r influence on tidal current profiles, is parameterized using a how-de pendent eddy viscosity. Recent work on the chaotic behavior of particl es released into two-dimensional tidal flow models and the use of adjo int models is also briefly considered.