Nearshore Hydrodynamics and Sediment Dispersal Along Eroding Permafrost Coasts—Insights From Acoustic Doppler Current Profiler Measurements Around Herschel Island–Qikiqtaruk (Yukon, Canada)

Permafrost coasts are eroding at an accelerating pace, delivering vast amounts of sediments, organic matter, nutrients, and pollutants into the Arctic Ocean. These fluxes play a crucial role in the coastal biogeochemical cycle, yet their magnitude, as well as the trajectory and fate of the eroded material, is largely unknown. Direct observations of hydrodynamics in the Arctic nearshore zone are needed to overcome this issue, but these are challenging and scarce. Here, we report on direct current measurements performed in the nearshore zone. We deployed two Acoustic Doppler Current Profilers (ADCP) in 7‐ and 12‐m water depth close to Herschel Island–Qikiqtaruk Yukon, Canada, to measure current velocities and directions throughout the water column. The data show that the currents change on a synoptic scale based on meteo‐oceanographic forcing. During storms, these currents exceed the threshold of bottom sediment remobilization. The mobilization potential in the nearshore zone is therefore primarily related to wind forcing but can be strongly diminished by the presence of sea ice. These observations have implications for the future state of the Arctic nearshore zone, because larger fetches and a longer open water season could enhance sediment mobilization and dispersal.