Wave Refraction on Southern Ocean Eddies

摘要

Motivated by differences in direction of propagation betweenthe modelled and measured waves observed at the SouthernOcean Flux Station (SOFS), we investigated the possible effectsof wave refraction on a Southern Ocean current field. We im-plemented a numerical model to describe the refraction of wavetrains when propagating over a spatially varying current fieldand to see how they would be affected as they approach the lo-cation of the SOFS.The model was applied to three typical swell directions ob-served in the Southern Ocean, coming from south (S), south-west (SW) and west (W). The regions of convergence (increas-ing energy) and divergence (decreasing energy) of the wave raysare defined for each situation, as well as the relative changes inwave energy, and hence wave height. It is shown that a spe-cific eddy located at southwest from the buoy can have stronginfluences in the wave propagation and, in the case of westerlyand southwesterly swells, can generate a clear divergence of thewave rays that would otherwise have reached the buoy locationif there were no currents.