Global source attribution for mercury deposition in the United States.
A multiscale modeling system that consists of a global chemical transport model (CTM) and a nested continental CTM was used to simulate the global atmospheric fate and transport of mercury and its deposition over the contiguous United States. The performance of the CTMs was evaluated against available data. The coefficient of determination (r2) for observed versus simulated annual mercury wet deposition fluxes over North America was 0.50 with average normalized error and bias of 25% and 11%, respectively. The CTMs were used to conduct a global source attribution for selected receptor areas. Three global emission scenarios were used that differed in their distribution of background emissions among direct natural emissions and re-emissions of natural and anthropogenic mercury. North American anthropogenic sources were calculated to contribute only from 25 to 32% to the total mercury deposition over the continental United States. At selected receptors, the contribution of North American anthropogenic emissions ranges from 9 to 81%; Asian anthropogenic emissions were calculated to contribute from 5 to 36%; natural emissions were calculated to contribute from 6 to 59%.
Seigneur
Christian
C
Atmospheric & Environmental Research, Inc., Suite 120, 2682 Bishop Drive, San Ramon, California 94583, USA. seigneur@aer.com
Vijayaraghavan
Krish
K
Lohman
Kristen
K
Karamchandani
Prakash
P
Scott
Courtney
C
D000393:Air Pollutants / Q000032:analysis*; D005544:Forecasting; D008628:Mercury / Q000032:analysis*; D008962:Models, Theoretical; D012680:Sensitivity and Specificity; D014481:United States
D000393:Air Pollutants; D008628:Mercury