Introduction to the US GEOTRACES North Atlantic Transect (GA-03): USGT10 and USGT11 Cruises

GEOTRACES is an international scientific collaboration by science-at-sea nations of the world to map the distributions of trace elements and isotopes in the water column throughout the world׳s ocean and to advance our understanding of the processes that lead to those distributions. In some ways, it continues the process and spirit of the GEOSECS program in the 1970s, where geochemists collaborated to measure the carbon, nutrient, and chemical tracer field in the major ocean basins. The difference is that in the subsequent 40 years geochemists (and their supporting analytical chemistry developments) have enabled labs throughout the world to measure properties that were beyond the grasp of GEOSECS. These include biologically important trace metals such as Fe, Zn, and Co and their chemical speciation, anthropogenic contaminants such as Pb and Hg, oxygen and nitrogen stable isotope ratios of the nutrients NO₃⁻ and NO₂⁻, stable isotope ratios of elements such as He, Fe, Zn, Cd, and trace radionuclides such as ²³⁰Th, ²³¹Pa, ¹⁰Be, and a host of other properties that are reported in this special issue.