Long-term trends of mono-carboxylic acids in Antarctica: comparison of changes in sources and transport processes at the two EPICA deep drilling sites

• Published in: Tellus B: Chemical and Physical Meteorology
• Main Authors: de Angelis, M., Traversi, R., Udisti, R.
• Other Authors: Laboratoire de glaciologie et géophysique de l'environnement (LGGE), 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 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)-Centre National de la Recherche Scientifique (CNRS), Chemistry Department, Università degli Studi di Firenze = University of Florence (UniFI)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: ice cores; polar atmosphere; formic acid; acetic acid; climatic cycles; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Antarc*; Antarctic; Antarctica; Dronning Maud Land; EPICA
• Online Access: https://insu.hal.science/insu-00845288; https://insu.hal.science/insu-00845288/document; https://insu.hal.science/insu-00845288/file/17331-54940-1-PB.pdf; https://doi.org/10.3402/tellusb.v64i0.17331

International audience We present here the first profiles of acetate and formate concentrations in Antarctic ice for time periods that include the great climatic changes of the past. Data are from two Antarctic deep ice cores recovered on the central East Antarctic Plateau (EDC) and in the Dronning Maud Land (EDML) facing the Atlantic Ocean (European EPICA Project). Except the sporadic arrival of diluted continental plumes during glacial extrema, the main source of acetate deposited over the EDC does not seem to have changed significantly over the past 300 kyr and is related to marine biogenic activity. A more detailed study of the past 55 kyr leads to the conclusion that acetate reaching the EDML during a large part of the last glacial maximum was emitted by the Patagonian continental biomass and was uptaken along with nitric acid at the surface of mineral dust. Changes in formate concentrations are characterised by less scattered and lower values at both sites during glacial periods. We propose that the present marine source of formic acid (Legrand et al., 2004) drastically decreased but did not completely vanish under cold climate conditions, whereas the share of methane oxidation in formic acid production became prominent.