Wave Energy Potential and Bimodal Spectral Structure on the Brazilian Continental Margin: A Climatological Assessment

This study presents a climatological assessment of wave-energy resources and spectral organization along the Brazilian continental margin using the Copernicus Marine WAVERYS global wave reanalysis. Monthly wave-energy density, total-wave power flux, and the contributions and directional structure of wind waves, primary swell, and secondary swell were evaluated together with sensitivities to temporal aggregation, period formulation, and bathymetric resolution. Power calculated from the three-hourly climatological cycle showed that temporal aggregation produced median relative differences below 1% across the 17 coastal states. Partition-reconstructed power based on VTM01 was 27.84% lower than the total-wave VHM0–VTM10 reference, although spatial correspondence remained high (Spearman correlation = 0.994) and state rankings were largely preserved (Spearman correlation = 0.980). Bathymetric aggregation changed the domain-wide estimate by only 0.12% but increased sensitivity to 1.66% within the 5–50 m depth band. Southeastern and southern Brazil exhibited the highest-energy conditions, which were predominantly unimodal, whereas the Northeast showed moderate energy and greater recurrence and energetic relevance of multicomponent wave conditions. These patterns were supported by complementary persistence and energy-weighted bimodality indices. The results provide comparative regional climatological indicators; monthly integrated partitions and the model resolution preclude their interpretation as site-specific, operational, or engineering resource estimates.