Assessing the Influence of Ocean-Wind-Wave Coupling on Marine Boundary Layer Wind Dynamics

Abstract Understanding and accurately forecasting marine boundary layer dynamics in coastal areas is essential for resource management and strategic planning. These areas are characterized by intricate air–sea–land interactions, which pose challenges to predictability. Traditional high-resolution models treat wave–ocean effects through parameterization in stand-alone simulations, potentially overlooking fine-scale processes and simultaneous feedbacks. In this study, we employ the Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) system to investigate the impacts of ocean–wind–wave interactions on coastal processes and marine boundary-layer winds. Focusing on the Mid-Atlantic Bight, simulations from July 2021–June 2022 are validated against available buoy observations. Compared to stand-alone atmospheric simulations, the fully coupled system reduces wind-speed and direction errors within the lowest 50 m of the atmosphere above sea level. Targeted experiments are conducted to isolate the contributions of (i) sea-surface temperature (SST) and (ii) wave-dependent surface roughness, with specific emphasis on land–sea-breeze dynamics and high-wave conditions. SST feedbacks improve prediction of land–sea-breeze-driven low-level jets (LLJs), by enhancing skill in occurrence rates, jet-nose speed, and nose height at diurnal timescales. Over the continental shelf, diurnal SST variations statistically significantly alter LLJ occurrence by up to 5% and jet-nose speed by ∼ 1 ms −1 during the late afternoon. Incorporating wave-induced roughness statistically significantly reduces near-surface wind-speed biases and improves residuals during Nor’easter events by 𝒪 (1 ms −1 ). These findings underscore the importance of resolving SST and wave roughness dynamics to improve predictions of coastal wind profiles.