J. Phys. IV France
Volume 107, May 2003
Page(s) 525 - 528

J. Phys. IV France
107 (2003) 525
DOI: 10.1051/jp4:20030356

Mercury speciation into tropospheric clouds

P.-A. Gauchard1, A. Dommergue1, C.P. Ferrari1, 2, P. Laj3 and C.F. Boutron1, 4

1  Laboratoire de Glaciologie et Géophysique de l'Environnement du CNRS, 54 rue Molière, Domaine Universitaire, BP. 96, 38402 Saint-Martin-d'Hères cedex, France
2  École Polytechnique Universitaire de Grenoble, Université Joseph Fourier, 28 avenue Benoît Frachon, BP. 53, 38041 Grenoble, France
3  aboratoire de Météorologie Physique, Université de Clermont-Ferrand, 24 avenue des Landais, 63177 Aubière cedex, France
4  Unités de Formation et de Recherche de Mécanique et de Physique, Université Joseph Fourier, Institut Universitaire de France, Domaine Universitaire, BP. 68, 38041 Grenoble, France

Cloud water bas been sampled at the Puy De Dôme (France) for mercury determination. The analysis of these samples gave us concentrations from about 10 to 50 ng/L and from about 0.8 to 3.5 ng/L for total mercury (Hg $_{\rm T}$) and for reactive mercury (Hg $_{\rm R}$) respectively. In a previous study based on analysis of Total Gaseous Mercury in the interstitial phase of clouds, mercury concentrations in cloud water were estimated to be around 1  $\mu$g/L. Comparing this assumption with our measurements, we suggest that Hg'could be the principal mercury species in cloud water. A kinetic study, which compares reduction and oxidation processes, supports our hypothesis. Assuming our assumption to be tme, precipitation is likely to contribute significantly to elemental mercury deposition.

© EDP Sciences 2003