This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
GEOTRACES is a newly initiated international oceanographic program to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the oceans and to establish an understanding of the sensitivity of these distributions to changing environmental conditions. A scientist from the University of Southern California plans to participate in the 2010 North Atlantic GEOTRACES cruise to collect and analyze samples for total dissolved copper (Cu) and copper speciation. The objective is to determine the relationship between Cu cycling and its speciation over wide range of oceanographic regimes (i.e., shelf and slope waters, oligotrophic surface and thermocline, eastern boundary upwelling) with a vast array of other parameters, particularly particulate metals and particle-reactive isotopes. Coupled with particulate metal and particle-reactive isotope data obtained by others, the role of speciation in influencing Cu:C and Cu:N in sinking particulate matter, and dissolved N:Cu and P:Cu ratios in deep water, will also be assessed. In addition, via a collaboration with two molecular biologists at no cost to the project, the ecotype population of cyanobacteria throughout the section will be characterized and the relationships between metal geochemistry and the control of cyanobacterial community structure will be established. As regards broader impacts, one postdoc and one graduate student would be supported and trained as part of this project.