A new framework to characterize Arctic Ocean eddies leveraging Lagrangian observations of sea ice

Ocean eddies spanning small-to-moderate length scales (1 to 100 km) are an essential element of the Arctic system, given their role in transporting heat and nutrients and changing freshwater budgets. Advances in satellite altimetry have allowed the detection of coherent structures within the upper bound of the energetic scale range (>50 km). However, detecting eddies under sea ice is not possible using conventional satellite altimetry. In this talk, we outline a new framework to identify upper-ocean eddies from Lagrangian statistics of sea ice plates or floes. First, we leverage our recently developed automatic ice floe tracker algorithm to retrieve Lagrangian ice floe measurements from satellite observations. Then, we implement our newly developed data-assimilation method to recover missed observations resulting from the susceptibility of optical imagery to atmospheric noise. Finally, we exploit the strong coupling between the motion of free-drifting ice floes and ocean eddies with surface expression to retrieve ocean eddy characteristics. We focus our study on the Beaufort Gyre, intending to evaluate the interannual variability of the eddy field in this region within the past two decades.