Tracing the New Arctic: Is drifting sea ice a vorticity meter of the ocean?*

Observing small-to-moderate length-scale ocean turbulence (1 to 100 km) and understanding its impact on large-scale currents remains a major unresolved problem in ocean dynamics. In the Arctic Ocean, the lack of high-resolution altimeter measurements and the inherent challenges of obtaining comprehensive in-situ measurements in ice-covered regions have limited our ability to analyze eddy processes and ice-ocean interactions in detail. Nonetheless, under-ice eddies have been shown to play a critical role in transferring heat and momentum and affecting the motion of sea ice floes in marginal ice zones. I will present advances by my group in the automatic identification and tracking of sea ice floes using optical satellite imagery. Our techniques provide a unique record of ice floe shapes, trajectories, and velocities to explore the rich dynamical structure of the sea ice field. The novelty of our framework is that the resulting observations of sea ice floes can be used as a proxy to infer the characteristics of ocean turbulence within the small-to-moderate length-scale range. I will present case studies in the Beaufort Gyre and Fram Strait, including an overview of recently awarded projects. Our long-term goal is to develop a new-generation sea ice product, providing a road map to understanding the dynamics of critical momentum and heat transfer processes in the Arctic Ocean.