The link between sea ice floe rotation and the Arctic ocean enstrophy spectra

Floating particles, such as debris, microplastics, or sea ice, have been widely used to infer oceanic flows. In ice-covered oceans, for instance, our group demonstrated that sea ice plates (floes), ranging from 0.5 to 2 m thick and up to 100 km across, can serve as effective Lagrangian tracers for characterizing surface ocean eddy kinematics at meso- and submeso-scales. Using our Ice Floe Tracker (IFT) algorithm, floe motion in Arctic regions that are typically inaccessible to in situ observations can be quantified, allowing the analysis of interannual trends using the full satellite record. While our previous work linked floe rotation to ocean vorticity, in this study we extend that framework to infer surface ocean enstrophy spectra from satellite-derived ice floe rotation. Using a coarse-graining approach, we treat each floe as a local spatial filter to compute the spectra. The method is validated through idealized sea ice-ocean simulations and applied to satellite observations using the IFT in the Beaufort Gyre (BG)–a major wind-driven Arctic ocean system. Our results reveal steepened spectral slopes at low sea ice concentrations, indicating enhanced mesoscale activity but suppressed submesoscale dynamics during the spring-to-summer transition. This approach provides a cost-effective pathway to generating spatially dense, time-resolved maps of eddy characteristics in the BG, extending back to 2003.