On the development and verification of a parametric parallel unstructured-grid finite-volume wind wave model for coupling with ocean circulation models

Abstract

A parallel, unstructured grid, finite-volume parametric wind-wave model is developed with the intention of coupling to three-dimensional unstructured grid ocean circulation models. The model is derived from a conservation of energy flux formulations. In the model, the shoaling, refraction, and wave dissipation, as well as exchange of current and Stokes drift momentum effects are considered. The unstructured non-overlapping triangle grid cells are adopted in order to fit the curvature of the coastline better. A second-order unwinding scheme in spatial space and a multidimensional positive definite advection transport algorithm (MPDATA) scheme in angle space are used to solve the wave energy equation. The model is parallelized using METIS for domain decomposition with good load balancing across computational nodes. The model has been tested for several idealized situations, and realistic wave simulations for Lake George (near Canberra, Australia) and Gulf of Mexico; the model results agree well with analytical solutions, laboratory observations, and field observations. It is shown that the present model is capable of predicting waves with reasonable accuracy against the observations. The developed model is effective and economical to couple with existing unstructured circulation models.