The chemical and structural properties of sea ice in the southern Beaufort Sea

The purpose of this study is to provide a detailed chemical and structural profile of first-year and multiyear Arctic sea ice. Ice cores were collected during April-May 1986 and 1987 near Prudhoe Bay, Alaska. Concentrations of Cl, Br, SO$\sb4$, Na, Ca, K, Mg, PO$\sb4$, SiO$\sb4$, NO$\sb3$, NO$\sb2$ and NH$\sb4$ were determined for samples chosen on the basis of structural ice type. Chemical and statistical analyses indicate that finer-grained structures incorporate more impurities and that major ion chemistry is controlled almost entirely by salinity. Mg is enriched in the ice indicating precipitation is occurring at temperatures higher than previously reported. K is depleted in the ice suggesting preferential drainage. Ratios of the major ions are the same for first-year and multiyear ice and are similar to that of seawater indicating that as the ice ages no significant changes occur in ice chemistry. Nutrient concentrations in the ice are enriched with respect to the underlying water indicating that biological activity occurs in the ice and processes other than the overall salinity effect and brine drainage are affecting nutrient concentrations within the ice