A two-dimensional numerical model is used to predict the shoaling and breaking of surface gravity waves, and the resulting longshore currents, for 5 days of the Nearshore Sediment Transport Study Santa Barbara experiment. Data with incident waves having narrow-banded frequency and directional spectra are selected for comparison in accord with the model assumptions of unidirectional and monochromatic waves. The rms wave height is used for expressing wave energy in the calculations. The current model includes bottom friction, lateral mixing, and nonlinear convective accelerations. The extensive field measurements of waves, including quantitative directional information, and longshore current distributions are used to test the model results. The predicted rms wave heights are consistent with the measurements. By tuning the model with field data of longshore currents, the comparison between the model and data shows good agreement, and the obtained values of free parameters are relatively constant for the five experiment days. |