Airborne noise propagation from offshore wind turbines into ocean environments: Influence of sea-surface waves and turbine wakes through advanced high-order modeling

Offshore wind energy is developing fast, but operational underwater noise poses growing risks to marine life. Existing propagation models are not capable of simultaneously capturing turbine wake refraction and wave-shaped air–water interface tilting under realistic sea states, often underestimating downstream noise footprints. This research article presents the first coupled high-order discontinuous Galerkin (DG) Large-Eddy Simulation with Gaussian-beam ray-tracing framework to critically evaluate these limitations and provide a new predictive capability. We simulate the DTU 10 MW turbine under rated and near-cutout conditions with flat and wavy sea surfaces. The results reveal that wake-induced refraction and a wavy sea surface expand the high-SPL underwater. For example, at 100 m depth under rated wind turbine operation, there is a noisy zone around 100 m downstream for a flat sea surface. However, for a wavy sea surface, the noisy zone expands to 200-300 m downstream. And local increasing of sound pressure levels due to wave is up to 20 dB. These findings critically demonstrate how combined wake/wave effects violate assumptions of conventional models and offer quantitative guidance for noise mitigation, turbine layout optimization, and marine spatial planning. The methodology will help advance sustainable offshore wind deployment by linking high-fidelity acoustics to ecological protection.