Numerical modeling of tide and current in Central Puget Sound: Comparison of a three‐dimensional and a depth‐averaged model

Abstract

A depth‐averaged and a three‐dimensional hydrodynamics model were applied in a study to evaluate quantitative methods for characterizing tide and current in one of the major basins of Puget Sound. The objective of the investigation was to assess the models' performance and operational requirements for future management applications. The study found that at the chosen horizontal spatial resolution scale of 762 m, both models were capable of reproducing major observed tide and tidal current characteristics in the study area and the differences between the results of the two models are small. Typical runs of the models with the current resolution require about 6–20 System Resources Units on a CRAY X/MP‐48 supercomputer. For future simulation of general tidal circulation and transport features in the Sound, the use of depth‐averaged models with spatial resolution of 800 m or less is recommended. For certain management problems around the Sound (for example, outfall siting, dredge material disposal) in which more detailed knowledge of the tidal current might be useful, the use of three‐dimensional models with finer spatial resolution (300 m or less horizontally and 15–50 m vertically) is suggested. The study also demonstrated that with increasing availability of computing power, wider use of multidimensional hydrodynamics models for estuarine environmental decision making as well as basic scientific research is very promising.