Distribution of Total CO₂, Nutrients, Chlorophyll-a in the Scotia Sea During Austral Summer

Abstract

Temperature, salinity, alkalinity, pH, nutrient, chlorophyll, and iron were measured within the upper 250 m water column around the Antarctic Polar Front in the Scotia Sea from late November to early December 2001. Temperature and salinity showed a rapid change across the Polar Front, and the temperature minimum layer existed only in the southern area of the Polar Front. Total CO2 and nutrient concentrations were relatively high and increased rapidly with water depth in the southern area of the Polar Front, which was resulted from upwelling of the Antarctic deep water containing high concentrations of total CO2 and nutrient. △C:△N:△P ratios measured in the northern and southern areas of the Polar Front were 75:11.4:1 and 84:12.5:1, respectively, which were lower than the Redfield ratio. △Si:△N ratio (3.65) measured in the southern area of the Polar Front was two times higher than that (1.95) in the northern area. These two ratios were higher than the ratio (1.0) measured in the temperate and tropical oceans. Chlorophyll concentrations were extremely high in the area of 59o~60oS, which was attributed to favorable environmental conditions for phytoplankton growth in this area, such as sufficient iron, high water column stability, and high silicate concentration.