Coupling of sea ice and ocean components in Earth System Models

A key requirement of Earth System Models is the conservation of heat, water, and salt. Traditionally coupled models have made simplifications in these fluxes due to the physics representation in each of the component models. For example, the fluxes of salt and fresh water between the sea ice and ocean assume a constant reference salinity of 4 psu in the sea ice and 34.8 psu in the ocean. With a recent transition to the Modular Ocean Model version 6 (MOM6) and the Los Alamos Sea Ice Model version 6 (CICE6) in the Community Earth System Model, this allows for natural boundary conditions between the sea ice and ocean. In this work we propose a set of water and salt fluxes during sea ice growth and melt that will account for the prognostic salinity in the sea ice and ocean.