Actually on coastal areas, the wind energy industry migrates to the offshore environment, where huge spaces are still available in stronger and better behaved wind conditions. The concerned flow is hold by a turbulent atmospheric boundary layer (ABL) where the ocean's dynamics might significantly alter the atmospheric flow through higher heat capacity and complex wind-wave interactions important in fairly common situations. Besides the departure of the ABL from onshore predictions, other important phenomena result from wind-wave interactions, creating specific (maybe extreme) sea state conditions and impacting global atmospheric and ocean circulations.

The ABL is mostly disturbed on a limited region referred as the wave boundary layer (WBL). Focusing in the WBL generated by non-equilibrium old-seas conditions, the free-surface position and velocities are here prescribed into a Large Eddy Simulation (LES) according to a fifth order Stokes solution. The swell disturbances on the WBL are explored through mean profiles and spectral analyses. An original non-linear definition of a wave induced flow is presented, considering correlated turbulent and wave induced motions thus accessing the coupled dynamics between those fields and inducing a natural precise definition of the WBL height. A robust definition of the wave induced flow and its coupling with turbulent dynamics would possibly allow its modeling in low-fidelity numerical models. Employing the proposed decomposition, the turbulent flow characteristics are recovered as expected in a flat bottom ABL, though some of its scales change considerably forced by the WBL below.