Wave Energy Variability Along the Continental Shelf of the Pacific Coast of Northern South America

Abstract:

Wave energy variability along coastlines depends on wave spatial distribution and dissipation over the continental shelf. From WAVEWATCH III modeled data, we calculate the energy flux for different locations along the Northern Pacific coast of South America to analyze changes in local wind waves and swell energy related to continental shelf morphology. Since the third-generation model accounts for wave reflection and scattering at sloping bathymetry a statistical correlation is made between slope changes in the continental shelf and wave energy distribution along the coast. Latitudinal changes encompass physical factors such as wind, bottom friction and shelf morphology which explain up to 50% of the wave energy flux distribution in gravity waves. Latitude also explains 72% and 56% of the wave energy frequency variability for the local wind waves and swell, respectively. We find a power-law relationship between depth and wave energy frequency variability suggesting that larger water depths increase the energy variability for swell and decrease the energy variability for local wind waves. Wave energy flux distributions suggest a morphologically controlled delivery of energy to the nearshore, likely dictating the morphodynamics of adjacent nearshore environments.