Desalination processes of sea ice revisited

We reexamine five processes that have been suggested to be important for the loss of salt from sea ice. These processes are the initial fractionation of salt at the ice-ocean interface, brine diffusion, brine expulsion, gravity drainage, and flushing with surface meltwater. We present results from analytical and numerical studies, as well as from laboratory and field experiments, that show that, among these processes, only gravity drainage and flushing contribute to any measurable net loss of salt. We show that during ice growth the salinity field is continuous across the ice-ocean interface. Hence there is no immediate segregation of salt at the advancing front.