Wave energy assessment using SWIM radar and high-resolution altimeter data

The paper focuses on estimating wave power density in Atlantic waters near the European coast. CryoSat-2 altimeter data were collocated with SWIM radar measurements. It was shown that significant wave height and zero-crossing wave period derived from altimeter data align well with SWIM measurements. The ratio of energy wave period to zero-crossing wave period (wave period ratio) is essential for estimating wave power density from altimeter data. A spatial and seasonal analysis of this parameter is presented for the first time based on SWIM radar measurements. The dependence of the wave period ratio on wave age was determined, and seasonal maps of this parameter show a pattern similar to the probability of swell-dominated sea occurrence. Uncertainties associated with using a constant wave-period ratio to calculate wave power density from altimeter data were evaluated. Without applying a correction, wave power density could be underestimated by up to 12%, depending on the location. The integrated methodology that enables refined wave power density assessment was developed based on the joint analysis of altimeter and SWIM radar data. The study was performed as part of the WAPOSAL (Wave Power & Satellite Altimetry) project (https://eo4society.esa.int/projects/waposal/).