Profile Properties of Undeformed First-Year Sea Ice

In many sea ice engineering problems the ice sheet has been assumed to be a homogeneous plate whose mechanical properties are estimated from the bulk salinity and average temperature of the ice sheet. Typically no regard has been given to the vertical variation of ice properties in the ice sheet or to the time of ice formation. This paper first reviews some of the mechanical properties of sea ice, including the ice tensile, flexural and shear strengths, as well as the ice modulus. Equations for these properties are given as functions of the ice brine volume, which can be determined from the ice salinity and temperature. Next a numerical, finite difference model is developed to predict the salinity and temperature profiles of a growing ice sheet. In this model ice temperatures are calculated by performing an energy balance of the heat fluxes at the ice surface. The conductive heat flux is used to calculate the rate of ice growth and ice thickness by applying the Stefan ice growth equation. Ice salinities are determined by considering the amount of initial salt entrapment at the icewater interface and the subsequent brine drainage due to brine expulsion and gravity drainage. Ice salinity and temperature profiles are generated using climatological data for the Central Arctic basin. The predicted salinity and temperature profiles are combined with the mechanical property data to provide mechanical property profiles for first-year sea ice of different thicknesses, grown at different times of the winter. AW