Coastal Model Performance Evaluation and Comparison

摘要

This study compares several ocean circulation models in coastal applications. Thecomparison is restricted to 3-D, primitive equation, free-surface models on sigma-like vertical coordinate systems. The models differ in their treatment of the barotropic flow, horizontal and vertical mixing, temporal and spatial differencing and other details. The physical accuracy and the numerical character of the models are evaluated and discussed on a variety of test problems. The coastal study processes include wave propagation, upwelling and downwelling regimes, and genesis and evolution of fronts. The study indicates that the solutions may sensibly differ from model to model. This is primarily due to: (1) different response to the calibration of the physical and numerical parameters, (2) perturbations in the dynamical balances. In general, differences in the primary features (such as front location, strength of the coastal jet) can be adjusted by adequate calibrations. Representation of the secondary features (such as internal wave propagation, temperature and salinity anomalies) may depend upon different parameterizations and numerical treatments of the same physical terms that may alter the relative importance of the dominant processes.