The Measurement of Shallow Ocean Currents Beneath Deformed Mobile Sea Ice Using Upward Looking Sonar Instruments

The under ice ocean currents are critical in the understanding of the boundary layer between the sea ice and the ocean, involving determination of the drag forces that sea-ice exerts on the upper water column and the related turbulence and mixing levels. A semi-automated algorithm has been developed, which accounts for the changes in sea ice drafts, to determine the nearest surface ocean current measurement level. Using long-term measurements from upward looking sonar datasets in the Chukchi and Beaufort Seas, the algorithm and its extensions to all current bins is investigated.