title: Atmospheric mercury depletion event study in Ny-Alesund (Svalbard) in spring 2005. Deposition and transformation of Hg in surface snow during springtime.
abstract: A field campaign was conducted in Ny-Alesund (78 degrees 54'N, 11 degrees 53'E), Svalbard (Norway) during April and May 2005. An Atmospheric Mercury (Hg) Depletion Event (AMDE) was observed from the morning of April 24 until the evening of April 27. Transport of already Hg and ozone (O3) depleted air masses could explain this observed depletion. Due to a snowfall event during the AMDE, surface snow Hg concentrations increased two fold. Hg deposition took place over a short period of time corresponding to 3-4 days. More than 80% of the deposited Hg was estimated to be reemitted back to the atmosphere in the days following the event. During the campaign, we observed night and day variations in surface snow Hg concentrations, which may be the result of gaseous elemental mercury (GEM) oxidation to divalent Hg at the snow/air interface by daylight surface snow chemistry. Finally, a decrease in the reactive Hg (HgR) fraction of total Hg (HgT) in the surface snow was observed during spring. We postulate that the transformation of HgR to a more stable form may occur in Arctic snow during spring.
authors.affiliation: Laboratoire de Glaciologie et Géophysique de l' Environnement du C.N.R.S., 54 rue Molière, BP 96, 38402 Saint Martin d'Hères, France. ferrari@lgge.obs.ujf-grenoble.fr <ferrari@lgge.obs.ujf-grenoble.fr>
authors.forename: Christophe P
authors.initials: CP
authors.lastname: Ferrari
authors.forename: Cyril
authors.initials: C
authors.lastname: Padova
authors.forename: Xavier
authors.initials: X
authors.lastname: Faïn
authors.forename: Pierre-Alexis
authors.initials: PA
authors.lastname: Gauchard
authors.forename: Aurélien
authors.initials: A
authors.lastname: Dommergue
authors.forename: Katrine
authors.initials: K
authors.lastname: Aspmo
authors.forename: Torunn
authors.initials: T
authors.lastname: Berg
authors.forename: Warren
authors.initials: W
authors.lastname: Cairns
authors.forename: Carlo
authors.initials: C
authors.lastname: Barbante
authors.forename: Paolo
authors.initials: P
authors.lastname: Cescon
authors.forename: Lars
authors.initials: L
authors.lastname: Kaleschke
authors.forename: Andreas
authors.initials: A
authors.lastname: Richter
authors.forename: Folkard
authors.initials: F
authors.lastname: Wittrock
authors.forename: Claude
authors.initials: C
authors.lastname: Boutron