During the next ten to twelve years, scientists from oceanographic laboratories around the world will participate in GEOTRACES -- a benchmark effort to investigate the distribution and behavior of chemicals in the sea that can give insight into the way the ocean works as a geophysical system. In this project, researchers at the University of Alaska at Fairbanks will be funded to participate in the May-June 2008 and in the June 2009 GEOTRACES intercalibration cruises in the Sargasso Sea and the North Pacific. During the May-June 2008 cruise, this principal investigator and his colleagues intend to compare their custom-built ATE/Vane iron sampler to the GEOTRACES sampling system and other water samplers for the contamination-free sampling of dissolved, colloidal and particulate trace metals. During the June 2009 cruise, this project will investigate sample storage procedures for Fe-binding organic ligands that minimize storage artifacts by providing on-board measurements of unfrozen freshly collected seawater samples and time series measurements of preserved samples. The sampler comparison studies will help establish ?default? sampling procedures for the US GEOTRACES program. The sample storage method studies will provide confidence to carry out a global survey of trace element speciation during the GEOTRACES program. These proposed works are critical for the success of the GEOTRACES intercalibration cruises and comply with the major goals of GEOTRACES project.
The proposed is expected to have broader impacts that extend beyond the international GEOTRACES program. It should provide important new insights for a variety of research activities that endeavor to understand the roles of oceanic trace element geochemical cycling in regulating marine ecosystem and the oceanic carbon cycle. Such understanding will help predict changes in natural oceanic environments and global climate due to human activities, and will help in the proper management of current and future marine resources. In addition, the proposed studies of sampler comparison and sample storage procedures, during the intercalibration cruises, will help develop proper methods for large scale trace elements sampling in the global ocean which will advance the field of oceanography in general.
