During late fall 2013, the US GEOTRACES Eastern Pacific Zonal Transect will survey the distribution of trace metals and isotopes (TEIs) in a region with low atmospheric deposition. As part of the International GEOTRACES Program, our project undertakes the collection, characterization, and distribution to the community of aerosol and rainfall samples along this transect. Bulk and size-fractionated aerosol samples collected on a 24 to 48-hour integrated basis, and event-based rain samples are analyzed for a large suite of TEIs in order to contribute towards the quantification of their atmospheric input. Aerosol leaches are conducted to determine seawater-soluble and ultrapure-water-soluble TEI fractions, and emphasize the determination of the size fractionation and redox speciation of seawater-soluble iron. Collaboration with researchers from other institutions will augment our effort to characterize and constrain estimates of atmospheric deposition. Surface seawater samples are analyzed for a suite of TEIs to help in the interpretation of our atmospheric deposition data. This work contributes towards the overall goal of the GEOTRACES Program by directly addressing objectives related to atmospheric deposition described in the Science Plan. These objectives are to establish the range of fractional aerosol solubility and to better quantify deposition across the global ocean.
Last updated: Oct 12, 2013