The P.I.'s propose to study spatial and temporal variations in the distributions and particulate fluxes of a suite of naturally occurring radioactive nuclides as part of the Joint Global Ocean Flux Study (JGOFS) in the equatorial Pacific. The radionuclides to be measured serve as ocean tracers that yield fundamental information about the rates of biogeochemical processes that govern the production and fate of biogenic particles in the oceanic water column. The study is designed to test the hypothesis that the uptake and release of soluble chemical species by particulate matter, and the formation and destruction of particle aggregates in the oceanic water column occur at rates that vary both spatially and temporally in response to variations in the rate of plankton production at the sea surface and the flux of organic matter leaving the surface layer. The data will be interpreted within the context of biological rate measurements and other data to be collected within JGOFS and will be used to test biogeochemical models.
