A global unstructured, coupled, high-resolution hindcast of waves and storm surge

TL;DR

This study presents a high-resolution, 50-year global hindcast of waves and storm surges using an unstructured mesh, significantly improving nearshore process resolution and accuracy for coastal hazard assessments.

Contribution

Developed a novel 50-year global hindcast system with 2-4 km resolution, fully coupled with circulation and wave models, enhancing nearshore process simulation compared to prior coarse-resolution models.

Findings

Good agreement with satellite, tide gauge, and buoy data.

Enhanced ability to reproduce nearshore dynamics.

Provides detailed wave spectral parameters at high temporal resolution.

Abstract

Accurate information on waves and storm surges is essential to understand coastal hazards that are expected to increase in view of global warming and rising sea levels. Despite the recent advancement in development and application of large-scale coastal models, nearshore processes are still not sufficiently resolved due to coarse resolutions, transferring errors to coastal risk assessments and other large-scale applications. Here we developed a 50-year hindcast of waves and storm surges on an unstructured mesh of >650,000 nodes with an unprecedented resolution of 2-4 km at the global coast. Our modelling system is based on the circulation model SCHISM that is fully coupled with the WWM-V (WindWaveModel) and is forced by surface winds, pressure, and ice coverage from the ERA5 reanalysis. Results are compared with observations from satellite altimeters, tidal gauges and buoys, and show good skill for both Sea Surface Height (SSH) and Significant Wave Height (Hs), and a much-improved ability to reproduce the nearshore dynamics compared with previous, lower-resolution studies. Besides SSH, the modelling system also produces a range of other wave-related fields at each node of the mesh with a time step of 3 hours, including the spectral parameters of the first three largest energy peaks. This dataset offers the potential for more accurate global-scale applications on coastal hazard and risk