Christophe P. Ferrari †,‡
† Laboratoire de Glaciologie et Géophysique de l' Environnement du
C.N.R.S., 54 rue Molière, BP 96,
38402 Saint Martin d'Hères, France.
‡ Polytech’ Grenoble, Université Joseph Fourier (Institut
Universitaire de France), 28 Avenue Benoît
Frachon, BP 53, 38041 Grenoble, France.
17.06.2005, 13.00 c.t.
Room S3120
During field experiments in Kuujjuarapik (Québec) in 2002,
Ny-Alesund, Svalbard, in 2003 and 2004, atmospheric particles, elemental gaseous
mercury, reactive gaseous mercury and ozone have been measured continuously. The
purpose was to study the atmospheric particle concentration evolution during
successive Atmospheric Mercury Depletion Events (AMDEs) so as to better
understand the origin of these phenomena. Assuming that these phenomena imply
either a chemical link either an association through transport, we studied air
masses trajectories in order to clearly define the origin of these AMDEs. We
show that AMDEs can have different origin, and the drop in Hg° concentration in
these places can be the result of already depleted air masses. Some of them
clearly indicate that the chemistry is more local or regional. The AMDEs seem to
appear when atmopsheric temperature were low (i.e. below –10°C) and atmopsheric
surfaces seem to play a key role in activating this chemistry. These different
AMDEs can then have different consequences in term of Hg deposition onto snow
surfaces and then on the Arctic environment.