Energy exchange over young sea ice in the central Arctic

TLDR

The study uses a simple heat‑transport model coupled with climatological air temperature and radiation data to predict how each component of the surface heat balance changes with ice thickness in the central Arctic. The model shows that in the cold season, young ice (0–0.4 m) supplies 10–100 times more net heat to the atmosphere than perennial ice, that heat fluxes plateau once ice exceeds 1 m, that turbulent fluxes dominate the thickness dependence, and that overall heat input from young ice matches or exceeds that from open water or thick ice.

Abstract

A simple model of heat transport through young sea ice is combined with climatological data on air temperatures and incoming radiation in the central Arctic to predict how each component of the surface heat balance is affected by changes in ice thickness. Results indicate that during the cold months the net heat input to the atmosphere from ice in the 0‐ to 0.4‐m range is between 1 and 2 orders of magnitude larger than that from perennial ice. Once the ice exceeds a meter in thickness, there is little change in any of the heat fluxes as the ice thickens. Although both the amount of absorbed shortwave radiation and the emitted longwave radiation depend on ice thickness, it is the turbulent fluxes which undergo the largest changes. The rate of heat exchange over thin ice is shown to be extremely sensitive to snow depth and assumed boundary layer temperatures. It is concluded that with the present ice thickness distribution in the central Arctic, total heat input to the atmospheric boundary layer from regions of young ice is equal to or greater than that from regions of open water or thick ice.