WAVERYS: a CMEMS global wave reanalysis during the altimetry period

As part of the Copernicus Marine Service, WAVERYS is the multi-year wave reanalysis that provides global wave data with a fine grid resolution of 1/5 degrees. This wave reanalysis covers the period 1993-2019 and disseminates 3-h integrated wave parameters describing the sea state at the ocean surface. The wave model used is the version 4 of the model MFWAM, which is driven by sea ice fraction and wind provided by the atmospheric reanalysis ERA5. The WAVERYS includes the assimilation of altimeter wave data and directional wave spectra provided by Sentinel-1. The wave reanalysis includes also wave-current interactions by using 3-h surface current forcing provided by the ocean reanalysis GLORYS. This paper highlights the assessment of wave parameters provided by the WAVERYS. The validation has been performed with independent altimeter significant wave heights and buoy wave data. The results show the good accuracy of scatter index of SWH (significant wave height) which is 8.7% in comparison with HY-2A altimeter. Moreover, we point out that scatter index of SWH from the WAVERYS is improved by about 9% with respect to the ERA5 wave dataset. We also indicate the good accuracy of swell propagation thanks to the assimilation of directional wave spectra. An analysis has been conducted for wave-current interactions and also discussions about extreme values and trend of time series are suggested.

Automated summary

WAVERYS is a multi-year wave reanalysis under the Copernicus Marine Service, providing global wave data with fine resolution using the MFWAM model driven by ERA5 atmospheric reanalysis. By assimilating data from various sources, it improves accuracy in wave parameters like significant wave height and swell propagation. The analysis also includes discussions on wave-current interactions, extreme values, and trends in time series.