Numerical study on atmospheric mercury over China

• 1、School of Atmospheric Sciences, Nanjing University, Nanjing 210093

Abstract：Atmospheric mercury chemistry and dry deposition were incorporated into Regional Atmospheric Environment Model (RegAEMs). Given on mercury emission inventory, the spatiotemporal variations of atmospheric mercury and its total deposition flux are investigated. Results from RegAEMS indicate that high annual mean Hg0, HgO, Hg(OH)2, HgCl2, and HgP loadings appear in the regions with large mercury emissions, in most regions over China exceed its global background level of 1.0 ng m-3 except those in West and Northwest China. There are significant seasonal variations for surface loadings of these five kinds of mercury, and they are the highest in February and March while are the lowest in August. Profiles of annual mean mercury loading in different sites over the regions indicate that there are high concentrations of primary mercuries (Hg0 and HgP) in low levels for the sites near the sources. In remote sites, the loading peaks of these kinds of mercury appear in higher levels. Due to the strongest removing rates of Hg0, its dry deposition flux is much lager in summer. Simulated total deposited Hg0, HgO, and HgP over the region are 163.9, 7.43, and 32.2 t in 2004.

Keywords： Atmospheric environment Atmospheric mercury Concentration characteristic Dry deposition Regional atmospheric Environment Modeling System