Uncertainty in numerical modeling of near-shore circulation over a bumped bottom

The uncertainties related to simulating near-shore circulation with phase-averaged models are investigated. The analysis is restricted to modeling features which are most often used in practical applications, as implemented in standard commercial models, with reference being made to the experimental results by Haller et al. (2002) on a physical, fixed bottom, scale model of a barred beach. The sensitivity of computed results to key parameters was investigated, and optimal sets of parameters were recognized. The results of the parabolic wave driver denoted a simple saturation model for broken waves to be optimal for the case at hand, with the breaking depth index being much lower than standard reference values. A similar analysis carried out on wave driven circulation showed an erratic behavior of values of the same parameters to be used to optimize computed results related to different quantities. Detailed analysis of the influence of bottom roughness prescription in the circulation model showed markedly irregular response of computed results.