In this project principal investigators will carry out sampling for the World Ocean Circulation Experiment (WOCE) hydrographic line along 135 degrees W from 30 degrees S to 60 degrees S and then eastward to the coast of South America. This constitutes Pacific WOCE hydrographic line "P-17S." In addition, the PIs will collaborate with other Scripps PIs to complete other WOCE lines, "P-19S," along 88 degrees W, and "P-16S," along 150 degrees W.