The export of mercury from Asia is studied by using the STEM-Hg model

It is estimated that Asian countries (including China, India, and South and North Korea) contribute 56% to the global mercury emissions to the atmosphere due to the heavy use of coal. The large amount of mercury emissions and the long life time of mercury in the atmosphere imply the possibility of the long range transport of mercury from Asia to North America. To better understand the fate and transport of mercury between these two continents, the STEM-Hg model was developed based on up-to-date mercury mechanisms in the atmosphere. Mercury aqueous phase oxidation-reduction reactions, sulfite and oxygen aqueous phase reactions along with mercury gas phase reactions are included in the model. The model simulates Hg(0), Hg(2+) and Hg(p). By running the model using new mercury emissions inventory in two domains, the ACE-Asia and the ICARTT domains, the contributions of long range transport to Hg fluxes in North America are evaluated.