Nutrient regimes in the marginal ice zone of the Greenland Sea in summer

Abstract

The surface layer (150n1) nutnent distribution (nitrate and nitrite, phosphate, silicate, ammonium) in the ice edge zone of Fram Strait was investigated during summer 1984 as part of the Marginal Ice Zone Experiment (MIZEX '84). The position of the ice edge was determined by the hydrography of the region, i. e the different water masses typical of the Greenland Sea (Polar Water. Atlantic Water and Intermediate Water). Nutrient concentrations reflected the different types of water Nutrient dstribution was characterized by strong vertical stratification and large gradients at water mass boundaries. Nutrient minima were correlated with high biomass concentrations in stratified surface waters. At frontal boundaries elevated chlorophyll a values were associated with abundant nutrients. Along 5 transects through the ice edge zone, distinct ammonium maxima were found at the depth of the chlorophyll a maximum or slightly below it. The results suggest that at least 3 different nutrient regimes can b e distinguished in the surface layer of the Greenland Sea ice edge zone.