In this project, the PI will carry out measurements and analysis of chemical tracers, Chlorofluorocarbons, as part of the World Ocean Circulation Experiment (WOCE) hydrographic line, P-17S, which covers a large area of the southeast Pacific Ocean. These measurements will be used to study the flow of thermocline waters in the South Pacific Subtropical Gyre, formation of Subantarctic Mode Water and Anarctic Intermediate Water, and their spreading properties, as well as other ocean circulation processes.