SPATIAL VARIABILITY OF SEA-ICE PROPERTIES IN THE NORTHWESTERN WEDDELL SEA

Arrays of sea-ice cores were taken at 0.25-, 2-, and 20-m spacing from three floes of presumably 2 years' age in the northwestern Weddell Sea. Texture, salinity, chlorophyll a, and nutrient concentrations were determined in order to study the small-scale variability of these properties. Their vertical distribution patterns are similar between core samples from a specific floe. Mean salinity exhibits generally low standard deviations between cores (mostly < 0.3 ppt; in one case as high as 0.95 ppt). At specific depth levels, very high differences may occur, such as maximum salinity differences of more than 10 ppt at the top of floes. Mean chlorophyll concentrations vary up to one order of magnitude on small scales, which is as high as the regional variability exhibited by cores from the entire study area. Excepting ammonium, concentrations of nutrients vary much less than chlorophyll. Individual profiles and variability of nutrients are tied to chlorophyll concentrations. The variability of salinity and chlorophyll seem linked to the distribution of large-scale, secondary pores within the ice.