Turbulent exchange coefficients for the ice/ocean interface in case of rapid melting

Abstract

In the marginal ice zones, drifting sea ice encounters large ocean heat fluxes and melting rates. However, as found from modelling studies and observations of ice melting, double difflisive effects at the ice/ocean interface limit the melting rates. In this paper, direct measurements of turbulent heat and salt fluxes from the marginal ice zone during rapid melting are presented. The strength of double diffusion is found to be significant and close to the range suggested from other studies. Calculated melting rates when double diffusive effects are present are compared to melting rates calculated from a traditional bulk parameterization of ocean heat flux for a range of temperatures and friction velocities often encountered within the marginal ice zones. This comparison shows that by ignoring double diffusive effects, melting rates are bverestimated by several cm per thy, which may have a significant impact on a predicted future ice cover. © 2009 by the American Geophysical Union.