Salt rejection by sea ice during growth

It is demonstrated that rejection of salt at a freezing ice-water interface takes place at least in part by cyclic convective processes occurring within the small interstitial spaces located in the first few centimeters of ice above the interface. This invalidates the assump-tion of the diffusive boundary ' layer utilized by previous authors and shows that near-interface temperatures are subject to cyclic variations. This result should be generally true for phase changes in aqueous solutions with floating ice, and it must be considered as a modification to current theories of solidification. It is shown that large vertical tubular struc-tures attended by smaller tributary tubes exist within the growing sea ice sheet; this arrange-ment almost certainly indicates horizontal migration of brine toward preferred drainage areas in a manner analogous to the catchment area of a river and its tributaries