Homogeneous sulfur isotope signature in East Antarctica and implication for sulfur source shifts through the last glacial-interglacial cycle

• Published in: Scientific Reports
• Main Authors: Ishino, Sakiko, Hattori, Shohei, Savarino, Joel, Legrand, Michel, Albalat, Emmanuelle, Albarède, Francis, Preunkert, Susanne, Jourdain, Bruno, Yoshida, Naohiro
• Other Authors: School of Materials and Chemical Technology, Tokyo Institute of Technology, 226‐8502 Yokohama, Japan, Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Sciences de la Terre (LST), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ), ANR-16-CE01-0011,EAIIST,Projet International d'exploration de la calotte polaire de l'Antarctique de l'Est(2016)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Antarctic; East Antarctica; Southern Ocean; Antarc*; Antarctica; ice core
• Online Access: https://hal.science/hal-02350372; https://hal.science/hal-02350372/document; https://hal.science/hal-02350372/file/Ishino-2019-Homogeneous%20sulfur%20isotope%20signatu.pdf; https://doi.org/10.1038/s41598-019-48801-1

International audience Sulfate aerosol (So 4 2−) preserved in Antarctic ice cores is discussed in the light of interactions between marine biological activity and climate since it is mainly sourced from biogenic emissions from the surface ocean and scatters solar radiation during traveling in the atmosphere. However, there has been a paradox between the ice core record and the marine sediment record; the former shows constant nonsea-salt (nss-) So 4 2− flux throughout the glacial-interglacial changes, and the latter shows a decrease in biogenic productivity during glacial periods compared to interglacial periods. Here, by ensuring the homogeneity of sulfur isotopic compositions of atmospheric nss-So 4 2− (δ 34 S nss) over East Antarctica, we established the applicability of the signature as a robust tool for distinguishing marine biogenic and nonmarine biogenic So 4 2−. Our findings, in conjunction with existing records of nss-SO 4 2− flux and δ 34 S nss in Antarctic ice cores, provide an estimate of the relative importance of marine biogenic So 4 2− during the last glacial period to be 48 ± 10% of nss-SO 4 2− , slightly lower than 59 ± 11% during the interglacial periods. Thus, our results tend to reconcile the ice core and sediment records, with both suggesting the decrease in marine productivity around Southern ocean under the cold climate.