This project is a component of the World Ocean Circulation Experiment (WOCE) Volunteer Observing Ship (VOS) program. Several investigators will participate in a long-term measurement and analysis project, including the deployment of expendable temperature (XBT) and conductivity-temperature-depth (XCTD) probes from ships transiting the Pacific. High resolution sampling and frequent repeats will provide data for the space-time analysis of the upper ocean circulation.