Current interaction in large-scale wave models with an application to Ireland

Abstract

A nested large-scale wave model that covers most of the Atlantic Ocean and focuses on generating accurate swell conditions for Ireland is presented and validated over the two years 2016 and 2017. The impact of currents is studied using the surface currents from the GLORYS product. Currents slightly reduce by 1\% the error of the model compared to altimetry data, but they explain most of the wave energy at scales less than 50 meters. The variability induced by currents is found to be more noticeable on the instantaneous fields, up to 50 cm. Track following observations indicate that wave refraction induced by mesoscale eddies is correctly captured. However, this modulation is of the same order as a shorter-scale variability appearing in the altimetry data, which makes it difficult to objectively assess the impact of currents.