Acknowledgements

C. Sabine and R. Key would like to thank all of the members of the DOE CO₂ survey team for helpful advice while they were building the underway system and for helping to run the system during the Indian Ocean survey. In particular they thank R. Weiss and R. Van Woy for calibration of standard gases and the captain and crew of the R/V Knorr for assistance throughout the survey. They also thank the chief scientists from each leg as well as the U.S. WOCE Hydrographic Programme Office for their assistance and cooperation with the underway measurements. This work was supported by a grant from the U.S. DOE's Office of Biological and Environmental Research (DE-FG02-93ER61540) and the Princeton University Department of Geosciences.