The monitoring of atmospheric mercury species in the Southern Indian Ocean at Amsterdam Island (38°S)

The role of oceans in the global cycle of mercury is still poorly characterized, mainly because of a lack a long-term data on atmospheric mercury concentrations in the remote Southern Ocean. In the frame of GMOS (Global Mercury Observation System), we present here the first results from a new monitoring station at Amsterdam Island in the Southern Indian Ocean. For the period January to April 2012, we recorded mean concentration of gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and particulate-bounded mercury (PHg) of 1.03 ng m 3, 0.37 and 0.34 pg m 3 respectively. While GEM concentrations showed little variations, RGM and PHg exhibited fast variations with alternation of value below the instrumental detection limit and maximum values up to 4 pg m 3.