Assessing the performance of an operational wave system within a Mediterranean beach monitoring programme

This work assesses the performance of an operational wave system in the Mediterranean Sea by comparing computed data with nearshore and deep water measured datasets. Nearshore data measurements were collected through a field experiment carried out at Poetto beach (Southern Sardinia, Italy) during April and May 2017. In addition to coastal observations, we use deep water wave data measured by a wave buoy in the Gulf of Lion. During the period of the experiment, an operational system including an atmospheric and a wave model ran once a day to predict the wave evolution out to 5 days in advance. We used a multi-grid approach in which a large grid extended over the entire Mediterranean basin and a fine grid covered the coastal seas surrounding the island of Sardinia. The comparison between simulations and measurements show that the operational wave system is able to satisfactorily reproduce the evolution of the significant wave height in deep waters where the relative error was 17%. The error exceeding 25% in coastal waters suggests that the use of a finer grid is advisable to accurately address nearshore wave transformation processes and wave generation driven by local meteorological forcing.