Tracing anthropogenic aerosol trace metal sources in the North Atlantic Ocean using Pb, Zn and Ni isotopes

• Published in: Marine Chemistry
• Main Authors: Zhang, Xingchao, Lemaitre, Nolwenn, Rickli, Jörg, Dominik, Suhrhoff, Tim, Jesper, Shelley, Rachel, Benhra, Ali, Faye, Saliou, Jeyid, Mohamed, Ahmed, Vance, Derek
• Other Authors: Departement Erdwissenschaften ETH Zürich (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), CAS Key Laboratory of Crust–Mantle Materials and Environments Hefei, School of Earth and Space Sciences Hefei, University of Science and Technology of China Hefei (USTC)-University of Science and Technology of China Hefei (USTC)-Chinese Academy of Sciences Beijing (CAS), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of East Anglia Norwich (UEA), Laboratoire d'ecotoxicologie, Institut National de Recherche Halieutique, Centre de Recherches Océanographiques de Dakar-Thiaroye, Institut Sénégalais de Recherches agricoles, Institut Mauritanien de Recherches Océanographiques et des Pêches (IMROP), Xingchao Zhang was supported by the China Scholarship Council (grant 201906340082), This research was funded by the Swiss National Science Foundation (grants 200020_165904)., ANR-13-BS06-0014,GEOVIDE,GEOVIDE, Une étude internationale GEOTRACES le long de la section OVIDE en Atlantique Nord et en Mer du Labrador(2013), ANR-11-CEPL-0005,ÉPURE,Éléments trace métalliques Perturbations climatiques Upwelling et REssources(2011), European Project: 101066172,IsoMargin
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: Ni isotopes; Pb isotopes; Zn isotopes; aerosol sources; surface ocean; North Atlantic Ocean; [SDE]Environmental Sciences; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; North Atlantic
• Online Access: https://hal.science/hal-04528807; https://hal.science/hal-04528807/document; https://hal.science/hal-04528807/file/Pre-print.pdf; https://doi.org/10.1016/j.marchem.2023.104347

International audience Atmospheric deposition of trace metals of natural or anthropogenic origin is an important input of micronutrients to the surface ocean. However, understanding its direct impact on oceanic element cycles is challenging due to scarce data, coupled to diverse aerosol sources and variable solubilities. Here, we present a dataset that combines Ni, Zn and Pb isotopes for samples from the Moroccan and Senegalese coasts and in the high latitude North Atlantic Ocean. We combine the new with published data for other circum-North Atlantic sources to assess the processes that determine the isotope signatures in different types of aerosols. We then use open marine aerosol data to investigate the impact of these signatures in the open ocean. Isotope analyses were conducted on bulk aerosols (TSP), on their ultra-high-purity water leachates, and on rainwaters. Aerosols characterized by crustal elemental abundances have isotope compositions similar to Saharan mineral dust. Mixing with anthropogenic aerosols from Europe/North Africa results in lower Pb-206/Pb-207 and Pb-208/Pb-207 values for the Eastern North Atlantic region. Higher Pb-206/Pb-207 at a given Pb-208/Pb-207, observed near the Canadian margin and occasionally at the Senegalese coast, points to anthropogenic inputs from North America. Based on trends in the aerosol data (e.g., delta Zn-66(JMC-Lyon) versus Pb-206/Pb-207, delta Ni-60(SRM986) versus Ni/V), we identify several anthropogenic sources of Zn and Ni. The delta Zn-66(JMC-Lyon) of low-temperature pollution (e.g., non-exhaust traffic emission) appears to be around -0.1 parts per thousand to 0.2 parts per thousand, while leachate delta Zn-66(JMC-Lyon) as low as -0.21 parts per thousand indicates contributions from high-temperature combustion or smelting processes. Among aerosols with good correlations between Ni and V, delta Ni-60(SRM986) > 0.40 parts per thousand traces Ni contributions from oil combustion. Other Ni-enriched sources, possibly originating from laterite or sulfide, show ...