Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 15, 8767-8779, 2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
10 Aug 2015
Source attribution and process analysis for atmospheric mercury in eastern China simulated by CMAQ-Hg
J. Zhu1,2, T. Wang1, J. Bieser3,4, and V. Matthias3 1School of Atmospheric Sciences, Nanjing University, Nanjing 210093, China
2Department of Energy and Environment, Zhejiang Prov. Development Planning & Research Institute, Hangzhou 310012, China
3Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, 21502, Geesthacht, Germany
4National aeronautics and space research center (DRL), Oberpfaffenhofen, 82234, Weßling, Germany
Abstract. The contribution from different emission sources and atmospheric processes to gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), particulate bound mercury (PBM) and mercury deposition in eastern China were quantified using the Community Multi-scale Air Quality (CMAQ-Hg) modeling system run with a nested domain. Natural sources (NAT) and six categories of anthropogenic mercury sources (ANTH) including cement production (CEM), domestic life (DOM), industrial boilers (IND), metal production (MET), coal-fired power plants (PP) and traffic (TRA) were considered for source apportionment. NAT were responsible for 36.6 % of annual averaged GEM concentration, which was regarded as the most important source for GEM in spite of obvious seasonal variation. Among ANTH, the influence of MET and PP on GEM were most evident especially in winter. ANTH dominated the variations of GOM and PBM concentrations with contributions of 86.7 and 79.1 %, respectively. Among ANTH, IND were the largest contributor for GOM (57.5 %) and PBM (34.4 %) so that most mercury deposition came from IND. The effect of mercury emitted from out of China was indicated by a > 30 % contribution to GEM concentration and wet deposition. The contributions from nine processes – consisting of emissions (EMIS), gas-phase chemical production/loss (CHEM), horizontal advection (HADV), vertical advection (ZADV), horizontal advection (HDIF), vertical diffusion (VDIF), dry deposition (DDEP), cloud processes (CLDS) and aerosol processes (AERO) – were calculated for process analysis with their comparison in urban and non-urban regions of the Yangtze River delta (YRD). EMIS and VDIF affected surface GEM and PBM concentrations most and tended to compensate each other all the time in both urban and non-urban areas. However, DDEP was the most important removal process for GOM with 7.3 and 2.9 ng m−3 reduced in the surface of urban and non-urban areas, respectively, in 1 day. The diurnal profile variation of processes revealed the transportation of GOM from urban area to non-urban areas and the importance of CHEM/AERO in higher altitudes which partly caused diffusion of GOM downwards to non-urban areas. Most of the anthropogenic mercury was transported and diffused away from urban areas by HADV and VDIF and increased mercury concentrations in non-urban areas by HADV. Natural emissions only influenced CHEM and AERO more significantly than anthropogenic. Local emissions in the YRD contributed 8.5 % more to GEM and ~ 30 % more to GOM and PBM in urban areas compared to non-urban areas.

Citation: Zhu, J., Wang, T., Bieser, J., and Matthias, V.: Source attribution and process analysis for atmospheric mercury in eastern China simulated by CMAQ-Hg, Atmos. Chem. Phys., 15, 8767-8779,, 2015.
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Short summary
This study estimated the contributions to mercury concentration and deposition in easter China from seven categories of emission sources by CMAQ-Hg. Also, this study focuses on diagnostic and process analyses for atmospheric mercury pollution formation and on identification of the dominant atmospheric processes for mercury.
This study estimated the contributions to mercury concentration and deposition in easter China...