Understanding the biogeochemical cycles and distribution of trace elements in the marine environment is one of the main challenges in chemical oceanography. We describe herein the trace metal composition of the uppermost surface ocean of various oceanographic regions (Arctic and Southern Oceans, subtropical Atlantic Ocean, and Mediterranean Sea). Our results show that trace metals in the top meter of the ocean are found in two clearly differentiated layers according to metal abundance and stoichiometry, namely the surface microlayer (SML) and its underlying subsurface water (SSW). Although metal concentrations in the subsurface dissolved fractions vary regionally and globally, it shows a singular metal stoichiometric signature. This work emphasizes the need to study of the SML as unique compartment to improve our understanding of the biogeochemical cycle of trace metals in the surface ocean, especially for metals, such as Pb, Fe and Cu, which are abundant in the SML.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This research is a contribution to future projects: i) THRESHOLDS project (CTM2005-24238-E) funded by the EU-FP6; ii) ATOS project, funded as part of the Spanish contribution to the International Polar Year (IPY) by the Spanish Ministry of Science and Innovation (POL2006-00550/CTM). This project is a contribution to the GEOTRACES cluster of the IPY; iii) RODA project: funded by the Spanish MEC National Plan (CTM2004-06842-C03-02/MAR); Financial support to E. G-O was given by CEI-MAR. The data used are listed in the references, figures, tables, and supplements. We thank the crew of the R/V Hespérides and BIO García del Cid for their dedicated and professional assistance, and the personnel of the UTM for their highly professional technical support.