Comparison of reanalysis datasets with historical wave buoy data in northern Scottish waters.

Abstract Many industries rely on wave data to understand the potential for wave energy extraction, or to understand the wave environment for the design of marine structures and to plan operations and maintenance. Three ocean reanalysis datasets, ERA5, WAVEWATCH III and Copernicus Global Ocean Waves Analysis and Forecast, are compared to in-situ wave buoy data collected along the north of Scotland. All reanalysis datasets correlated well with the wave buoy data, with the Copernicus Global Ocean Waves Analysis and Forecast dataset being statistically the closest to the buoy data. However, all three reanalysis datasets underpredict significant wave height during extreme wave events. From comparisons of the wave buoy data at one site, it was found that although extreme events are underpredicted, the WAVEWATCH III reanalysis data performed the best, although still under predicted extreme wave heights. Of the reanalysis models compared against wave buoy data here, it is suggested that for extreme wave analysis the WAVEWATCH III model is recommended, whilst for long term statistics and weather windowing the Copernicus Global Ocean Waves Analysis is a good option. Whilst reanalysis data sets are a valuable resource for marine renewable energy, developers should be aware of the limitations of these datasets, in particular for extreme wave conditions.