Development of a nested local scale wave model for a 1/4 scale wave energy test site using SWAN

Abstract

ABSTRACTA numerical wave model is developed to simulate wave conditions at the 1/4 scale wave energy test site in Galway Bay on the west coast of Ireland. The Simulating Waves Nearshore gridded wave model (version 41.01) is used and a nesting methodology has been implemented to downscale from oceanic scale to a local scale. The nesting methodology does not require the development of a global wave model and instead uses freely available data from existing global models to provide boundary conditions to the regional coarse model. The nesting methodology can be relatively easily implemented for different parts of the world's oceans depending on available data and study requirements. In the present application, the regional coarse domain covers a large area of the north-eastern Atlantic Ocean at a resolution of 0.05° and the local Galway Bay domain is resolved at 0.0027° (approximately 300 m). Boundary conditions for the local high-resolution model are supplied from the coarse model. A detailed description of model input preparation is presented. The models were calibrated against wave buoy stations within the north-eastern Atlantic Ocean for the period of November 2013 and sensitivity tests were conducted on domain size, wave growth formulations and boundary specification. Model validation was conducted for a 3-year hindcast from 2011 to 2013 and it is shown that the developed wave model performs satisfactorily for this longer period and is therefore suitable for use as a forecast model.