Eddy-Induced Dispersion of Sea Ice Floes at the Marginal Ice Zone

Abstract

Ocean heat exchanges at the marginal ice zone (MIZ) play an important role in melting sea ice. Mixed-layer eddies transport heat and ice floes across the MIZ, facilitating the pack's access to warm waters. This study explores these frontal dynamics using disk-shaped floes coupled to an upper-ocean model simulating the sea ice edge. Numerical experiments reveal that small floes respond more strongly to fine-scale ocean currents, which favors higher dispersion rates and weakens sea ice drag onto the underlying ocean. Floes with radii smaller than resolved turbulent filaments (∼2–4 km) result in a wider and more energetic MIZ, by a factor of 70% each, compared to larger floes. We hypothesize that this floe size dependency may affect sea ice break-up by controlling oceanic energy propagation into the MIZ and modulate the sea ice pack's melt rate by regulating lateral heat transport toward the sea ice cover.