Evidences of modifications in the size distribution of particles during a mercury depletion event at Kuujjuarapik/Whapmagoostui, Québec (Canada)

During a field experiment at Kuujjuarapik/Whapmagoustui (55°31N, 77°75W), Quebec, we have pointed out modifications in the size distribution of particles during a Mercury Depletion Event (MDE). We observed an increase of atmospheric particles concentrations in the ambient air, correlated with depletions of ozone and atmospheric mercury. These increases were followed by a change in the size particles distribution. Assuming that the divalent mercury species formed during the MDE could be adsorbed onto particles, this is likely to contribute to higher deposition fluxes of oxidised mercury on the snow pack.