The Influence of Wave Events on Open Water Suspended Sediment Fluxes on the Alaskan Beaufort Sea Shelf: A Numerical Modeling Study

Abstract Suspended sediment fluxes on continental shelves impact geomorphology, habitats, and biogeochemistry. In the coastal Arctic, the rate at which sediment is transported to locations where it can be sequestered also impacts the fate of carbon from thawing permafrost. This study used a numerical model to analyze the role of wave events on open water suspended sediment fluxes over hourly to monthly timescales. A coupled hydrodynamic—sediment transport model, the Regional Ocean Modeling System—Community Sediment Transport Modeling System, was implemented within the Coupled Ocean‐Atmosphere‐Wave‐Sediment Transport (COAWST) Modeling System for the 2020 open water season on the Alaskan Beaufort Sea shelf. Results showed that wave‐ and current‐induced bed shear stresses were frequently capable of resuspending sediment. Waves dominated bed shear stresses in depths shallower than 10 m and currents dominated in depths deeper than 20 m. Suspended sediment flux directions oscillated with the currents, which were eastward on average. However, since large waves tended to occur during westward currents, time‐averaged suspended sediment fluxes on the inner shelf were westward. Sensitivity tests were performed where significant wave heights were (a) set to zero and (b) doubled, which showed that waves increased the fraction of time that sediment could be resuspended by up to 50% and increased westward suspended sediment fluxes on the inner shelf. Overall, the results improve our understanding of how waves impact sediment fluxes on the Beaufort Sea shelf during the open water season and suggest that terrestrially derived sediment may be transported westward along the inner shelf.