Hindcasting the Adriatic Sea near-surface motions with a coupled wave-current model

Abstract

Prediction of near-surface dynamics is one of the most challenging problems in oceanography because of the combined effects of waves, currents and turbulence. In this work an implementation of the Regional Ocean Modeling System (ROMS), two-way coupled to the Wind Wave Model II (WWM II), is used as the computational platform for the numerical experiments designed to evaluate the wave contribution to dynamics in the near surface region. To that end we apply recent concepts in physics of spectral wave modeling to close the momentum balance in the surface boundary layer. To force the ROMS and WWM II models and to assess their modeling skill we use observations and model results made during 2002-2003 in the Adriatic Sea. When all effects were included in the simulation, comparison with top-bin Acoustic Doppler Current Profilers (ADCP) measurements showed certain improvements. The mean error is reduced at most stations and the root mean square error decreased by 11% at all ADCP moorings and by 24% at four of them but the errors remain large due to the errors of the wind forcing. Our results also point to the importance of computing the Stokes drift from the full wave spectra instead of using a simplified truncation formula. © 2012. American Geophysical Union. All Rights Reserved.