Salt transport in artificial snow on sea ice: laboratory experiments

Salt within snowpacks on first-year sea ice affects snow properties by reducing the melting point, which can increase liquid water content and alter snowpack evolution. These changes lead to modifications in dielectric properties, which in turn influence snow and sea ice geophysical retrievals from radar remote sensing. In this study, we conducted laboratory experiments with artificial sea ice to examine how brine, originating from sea ice, influences the salinity of overlying snow. Our results reveal strong positive correlations (0.80 < r < 1.00) between the initial water salinity and volume of the created sea ice discs, and the overlying bulk snow salinity. The impact of brine migration as a function of snow grain size (0.710–1 mm, 0.355–0.710 mm and < 0.35 mm) and snow structure was explored, with grains less than 0.35 mm diameter leading to a basal snow salinity value seven times higher than grains in the 0.710 - 1 mm range. Furthermore, the presence of an ice layer within the snowpack was found to limit upward brine movement. These findings improve understanding of snow–ice brine interactions and provide critical insights towards enhancing the accuracy of remote sensing retrievals over sea ice regions.