Langmuir turbulence in the Arctic Ocean: insights from a coupled sea ice–wave model

Abstract. Upper ocean mixing governs the vertical transport of heat, momentum, and tracers in the ocean surface boundary layer (OSBL), yet large-scale climate models often misrepresent its underlying processes, leading to significant uncertainty in sea ice and ocean predictions. Langmuir turbulence (LT) is one of the primary mechanisms of mixing in the open ocean and is generated by the interaction of wind stress and wave-induced Stokes drift. Observations have confirmed LT activity in leads, polynyas, and the marginal ice zone (MIZ), however its spatial and seasonal variability remains poorly constrained. In this study, we conduct the first Arctic-wide assessment of LT potential using a coupled sea ice–wave model that integrates neXtSIM and WAVEWATCH III. We analyze the spatiotemporal variability of LT by examining model-resolved turbulent dissipation and vertical kinetic energy within the OSBL. Our analysis reveals that LT potential is higher in the MIZ during melt and freeze-up, when partial sea ice cover allows intermittent wave propagation. Under these conditions, LT commonly coexists with wind-driven shear, forming a mixed-forcing regime that shapes upper-ocean energetics in response to evolving sea ice and wave states. Sea ice concentration and wind–wave alignment strongly influence the intensity and distribution of LT-driven mixing. On average, LT contributes roughly 15 % of the total upper-ocean dissipation in the Arctic MIZ, with episodic wave-driven events during transitional ice periods doubling local mixing rates compared to wind-only conditions. This analysis highlights the energetic role of wave-induced mixing in the upper ocean, with potential implications for vertical momentum transport, mixed layer structure, and sea ice–ocean interactions in the Arctic.