9634612 Cane This award will support a study of the relationship between radiocarbon variability and circulation in the upper waters of the tropical Pacific Ocean. Specific topics include: 1. the physical processes which determine the distribution and variability of tropical sea surface Carbon-14; 2. the physics determining the observed thermocline inventory of bomb Carbon-14; and, 3. the pathways and timescales for the exchange of thermocline waters between the subtropical and tropical gyres. This is a collaborative study, in which scientists at Princeton will focus on analysis of historical records of C14 found in coral reefs, while scientists at Columbia University will apply numerical modeling techniques to the problem.