Understanding Melting due to Ocean Eddy Heat Fluxes at the Edge of Sea-Ice Floes

Abstract

Understanding how upper-ocean heat content evolves and affects sea ice in the polar regions is necessary to predict past, present, and future weather and climate. Sea ice, a composite of individual floes, varies significantly on scales as small as meters. Lateral gradients in surface forcing across sea-ice concentration gradients can energize subgrid-scale ocean eddies that mix heat in the surface layer and control sea-ice melting. Here the development of baroclinic instability near floe edges is investigated using a high-resolution ocean circulation model, an idealization of a single grid cell of a climate model partially covered in thin, nearly static sea ice. From the resulting ocean circulation we characterize the strength of eddy-induced lateral mixing and heat transport, and the effects on sea-ice melting, as a function of state variables resolved in global climate models.