Water mass and tracer spreading in the South Atlantic

M. Vanicek


Hydrographic, nutrient and tracer data from WOCE and pre-WOCE sections are
used in an inverse model to determine the water mass flow in the South
Atlantic. Bottle data are interpolated to correspond to the CTD data
coverage by applying multilinear regression methods. This procedure
provides a property data set with a uniform data distribution pattern.
Constraints for the inverse model are the overall salt balance and balances
of other properties as well as flow conditions inferred from moored current 
observations.

The main objective is an improved understanding of the spreading of North
Atlantic Deep Water (NADW) in the region between the Atlantic equatorial
zone and the circumpolar belt. It is checked whether balance quantities can
be improved by the additional information on the flow which is obtained by
including natural and anthropogenic tracers in the data set. Results are
presented on spreading patterns and quantitative fluxes of various
properties, with an emphasis on the NADW, particularly the branching near
the Vitoria-Trindade-Ridge and the flow patterns at the Mid-Atlantic Ridge.