Fast depletion of gaseous elemental mercury in the Kongsvegen Glacier snowpack in Svalbard

• Published in: Geophysical Research Letters
• Main Authors: Fain, Xavier, P. Ferrari, Christophe, Gauchard, Pierre-Alexis, Magand, Olivier, Boutron, Claude
• Other Authors: 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), Polytech' Grenoble, Université Joseph Fourier - Grenoble 1 (UJF), Unité de Formation et de Recherche de Physique
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2006
• Subjects: Chemical kinetic and photochemical properties; Constituent sources and sinks; Geochemical cycles; Troposphere; Snow; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Kongsvegen; Svalbard; glacier
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-00375463; https://hal-insu.archives-ouvertes.fr/insu-00375463/document; https://hal-insu.archives-ouvertes.fr/insu-00375463/file/2005GL025223.pdf; https://doi.org/10.1029/2005GL025223

International audience Gaseous elemental mercury (GEM, Hg°) was measured in the snowpack interstitial air on the Kongsvegen Glacier (Svalbard) between the surface and 190 cm depth. A rapid depletion of GEM from ∼5 to 0.4 ng.m−3 in the snowpack air was measured in less than 8 hours at a calculated depletion rate of ∼0.5–0.7 ng.m−3.h−1 while concentration of GEM above the snow stayed constant about 1.7 ng.m−3. This depletion could only be explained by chemical processes and this study suggests that Br. could be the most important reactant for the oxidation of GEM in the interstitial snow air. The lifetime of GEM was estimated to be ∼10 minutes with second order reaction rate constant between GEM and Br. of about ∼2 × 10−11 cm−3.molecule−1.s−1. These first experimental kinetic values for GEM oxidation in the snow air are in good agreement with both theoretical and modelling studies previously reported.