Linkages between salinity and brine channel distribution in young sea ice

A high-resolution study of bulk salinity was undertaken on laboratory-grown sea ice to determine the extent of spatial variability of salinity and whe ther this was associated with brine channel structures. Ice samples at two different stages of development were compared with respect to physical stat e, brine distribution, and brine channel structures. Cold, growing sea ice is shown to have steep bulk salinity gradients and a highly variable brine distribution that is closely linked to the location and morphology of brine channels. Areas of high bulk salinity are found to correspond directly to the positions of the brine channels, and these areas are surrounded by ice that shows significant brine depletion. It is observed that redistribution of the brine occurs as the ice cover goes through warming and melting phase s. The redistribution is attributed to an increase in porosity and pore con nectivity permitting migration of brine through the ice. The distribution o f brine in "warm" ice is shown to be more homogeneous and independent of br ine channel structures. A number of mechanisms exploiting the enhanced mobi lity of brine in warm sea ice are used to explain the changes in the salini ty profiles and brine distribution.