Atmospheric iron fluxes over the last deglaciation: Climatic implications

• Published in: Geophysical Research Letters
• Main Authors: Gaspari, Vania, Barbante, Carlo, Cozzi, Giulio, Cescon, Paolo, F. Boutron, Claude, Gabrielli, Paolo, Capodaglio, Gabriele, Ferrari, Christophe, Robert Petit, Jean, Delmonte, Barbara
• Other Authors: Environmental Sciences Department, University of Ca’ Foscari Venice, Italy, Institute for the Dynamics of Environmental Processes-CNR, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS), Unité de Formation et de Recherche de Physique, Université Joseph Fourier - Grenoble 1 (UJF), Polytech' Grenoble, Dipartimento di Scienze dell'Ambiente e del Territorio (DISAT), Università degli Studi di Milano Milano (UNIMI), European Project for Ice Coring in Antarctica (EPICA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2006
• Subjects: Greenhouse gases; Ice cores; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Southern Ocean; ice core
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-00375478; https://hal-insu.archives-ouvertes.fr/insu-00375478/document; https://hal-insu.archives-ouvertes.fr/insu-00375478/file/2005GL024352.pdf; https://doi.org/10.1029/2005GL024352

International audience A decrease in the micronutrient iron supply to the Southern Ocean is widely believed to be involved in the atmospheric CO2 increase during the last deglaciation. Here we report the first record of atmospheric iron fluxes as determined in 166 samples of the Dome C ice core and covering the last glacial-interglacial transition (22–9 kyr B.P.). It reveals a decrease in fallout flux from 24 × 10−2 mg Fe m−2 yr−1 during the Last Glacial Maximum to 0.7 × 10−2 mg Fe m−2 yr−1 at the onset of the Holocene. The acid leachable fraction of iron determined in our samples was the 60% of the total iron mass in glacial samples, about twice the value found for Holocene samples. This emerging difference in iron solubility over different climatic stages provides a new insight for evaluating the iron hypothesis over glacial/interglacial periods.