Special issue  

GEOTRACES is an international scientific collaboration that aims to improve the understanding of biogeochemical cycles and large-scale distribution of trace elements and isotopes (TEIs) in the marine environment. The central focus of this programme is a series of cruises – GEOTRACES sections – that cover the global ocean. In the North Atlantic, a first zonal transect was carried out by the US in 2010–2011 (GEOTRACES Section GA03; Boyle et al., 2015, and articles in the Deep Sea 2 special issue). The GEOVIDE cruise is the GEOTRACES Section GA01 led by the French community and carried out in 2014. The cruise track (North Atlantic and Labrador Sea) is located in a crucial area for the Earth climate and the thermohaline circulation as it represents a major overturning area of the so-called Meridional Overturning Circulation (MOC). Moreover, TEI distribution is poorly constrained in this area. The main scientific objectives of GEOVIDE are to (i) better know and quantify the MOC and the carbon cycle in a decadal variability context, adding new key tracers; (ii) map the TEI distribution with their physical and chemical speciation along a full-depth, high-resolution ocean section; (iii) investigate the link between the TEIs and the production, export, and remineralisation of particulate organic matter; (iv) characterise the TEI sources and sinks and quantify their fluxes at the ocean boundaries; and (v) better understand and quantify the palaeoproxies ^231Pa/²³⁰Th, ε_Nd, and δ³⁰Si. This special issue will present the first outputs of this interdisciplinarity (physical oceanography, geochemistry, and biogeochemistry) and international collaborative project, based on a 47-day oceanographic cruise on the R/V Pourquoi Pas? (May–June 2014).