Pollard, Raymond T., and Jane F. Read

Southampton Oceanography Centre, Southampton SO14 3ZH, UK, Tel: 0 (44) 2380596433, Fax: 0 (44) 2380596204, Email: rtp@soc.soton.ac.uk

Nutrients in the Southern Ocean

During the last 10-15 years, numerous high quality sections across the Southern Ocean have been sampled during WOCE and JGOFS. These data sets are being examined to map and interpret the circumpolar and meridional structure of nutrients, as a contribution to question 3 of Southern Ocean JGOFS: What are the major features of spatial and temporal variability in the physical and chemical environments and key biotic factors? In particular, by interpolating nutrients onto neutral density surfaces, we seek to examine to what extent physical processes determine nutrient distributions, and whether the biological processes of nutrient uptake and remineralisation can be quantified. Isopycnic advection is clearly the dominant mechanism. For example, a band of high silicate and nitrate stretching across the South Atlantic beneath the Polar Front is the signature of high nutrient water from the South Pacific being advected by the Polar Frontal Jet of the Antarctic Circumpolar Current.