Effects of Wave-Current Interaction on Overwrapping Submesoscale Eddies and Unsteady Littoral Currents

Abstract

Effects of two-way wave-current interaction (WCI) on the surfzone-inner shelf circulations affected by submesoscale eddies and unsteady littoral currents are investigated with the ROMS-WEC model (Uchiyama et al., 2010) coupled tightly with a spectrum-peak wave model to account for both wave effects on currents (WEC) and current effects on waves (CEW) (e.g., Uchiyama et al., 2009). Eddy activity around the outer edge of the surfzone is enhanced when CEW is considered. The key mechanism to induce the surfzone-inner shelf dynamical interaction and enhancement of offshore eddy activity is considered to be CEW that weakens the offshore component of the littoral currents. In turn,offshore eddy activity is attenuated by WEC, demonstrating that WCI plays an essential role not only in the sufzone but also in the shelf region.