A global high-resolution CMIP6 ensemble of wave climate simulations and projections using a coastal multigrid: Configuration and performance evaluation

This study presents a comprehensive evaluation of a high-resolution wave climate ensemble, driven by eight CMIP6 General Circulation Models (GCMs), using a coastal multigrid approach based on Spherical Multiple-Cell (SMC) grid. The use of the SMC grid allows for global wave climate simulations refined to high resolutions up to 6 km in coastal regions, where complex interactions between wind, waves, and bathymetry demand more precise modelling. The ensemble’s performance is assessed against wave reanalysis datasets and near-coastal in-situ wave observations, with a focus on key wave climate parameters: significant wave height, mean wave period, peak wave period, and mean wave direction. Results show that the ensemble is able to accurately represent the historical wave climate across diverse regions, excelling in coastal areas, when compared with previous similar datasets, namely across Europe, North America and the Maritime Continent. The multi-resolution SMC grid captures complicated coastal wave patterns and improves the representation of coastal wave dynamics. The ensemble’s ability to simulate both seasonal variability and extreme wave events highlights its potential for high-resolution global wave climate projections, with multiple applications for coastal management and adaptation strategies, marking an advancement in wave climate modelling through its integration in high-resolution, multigrid frameworks.