Methodology for a Regional Tidal Model Evaluation, With Application to Central California

摘要

Observations from disparate observational assets, including tide gauges, moorings, and high-frequency (HF) radars, were used to depict the tidal variability, and to evaluate model tidal simulations, for a region off central California, including the Monterey Bay. For this study, the hydrodynamic model was forced only with tides derived from a large-scale model for the northeast Pacific Ocean. Homogeneous density, and initially horizontally uniform density stratification, cases were considered. The model successfully reproduced tidal sea-surface height variations within the model domain, a determined by comparisons with sea level or bottom pressure measured at six locations. To achieve tidal currents with realistic amplitudes, as determined from HF radar and moored measurements, it was found that barotropic velocity, as well as sea level, from the large-scale regional tidal model must be included in specifying the open-boundary condition. However, even with such forcing, the model with homogeneous density field under-predicted the semidiurnal and diurnal barotropic currents as estimated from depth-averaged currents measured at 11 locations. In the diurnal frequency band, the observed surface and nearshore depth-averaged currents are likely influenced by meteorological forcing, which was not included in the model.