The gaseous or particulate forms of divalent mercury(HgⅡ)significantly impact the spa-tial distribution of atmospheric mercury concentration and deposition flux(FLX).In the new nested-grid GEOS-Chem model,we try to modify the HgⅡ gas-particle partitioning rela-tionship with synchronous and hourly observations at four sites in China.Observations of gaseous oxidized Hg(GOM),particulate-bound Hg(PBM),and PM2.5 were used to derive an empirical gas-particle partitioning coefficient as a function of temperature(T)and organic aerosol(OA)concentrations under different relative humidity(RH).Results showed that with increasing RH,the dominant process of HgⅡ gas-particle partitioning changed from physical adsorption to chemical desorption.And the dominant factor of HgⅡ gas-particle partition-ing changed from T to OA concentrations.We thus improved the simulated OA concen-tration field by introducing intermediate-volatility and semi-volatile organic compounds(I/SVOCs)emission inventory into the model framework and refining the volatile distribu-tions of I/SVOCs according to new filed tests in the recent literatures.Finally,normalized mean biases(NMBs)of monthly gaseous element mercury(GEM),GOM,PBM,WFLX were reduced from-33％-29％,95％-300％,64％-261％,117％-122％to-13％-0％,-20％-80％,-31％-50％,-17％-23％.The improved model explains 69％-98％of the observed atmospheric Hg decrease during 2013-2020 and can serve as a useful tool to evaluate the effectiveness of the Minamata Convention on Mercury.

Kaiyun Liu;Qingru Wu;Shuxiao Wang;Xing Chang;Yi Tang;Long Wang;Tonghao Liu;Lei Zhang;Yu Zhao;Qin'geng Wang;Jinsheng Chen

State Key Joint Laboratory of Environment Simulation and Pollution Control,School of Environment,Tsinghua University,Beijing 100084,China;State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex,Beijing 100084,China;Institute of Atmospheric Environment,Guangdong provincial academy of environmental science,Guangzhou 510045,China;China National Environmental Monitoring Centre,Beijing 100012,China;State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing,210023,China;Center for Excellence in Regional Atmos.Environ.,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China

环境科学学报（英文版）

[1]Kaiyun Liu;Qingru Wu;Shuxiao Wang;Xing Chang;Yi Tang;Long Wang;Tonghao Liu;Lei Zhang;Yu Zhao;Qin'geng Wang;Jinsheng Chen-.Improved atmospheric mercury simulation using updated gas-particle partition and organic aerosol concentrations)[J].环境科学学报（英文版）,2022(09):106-118

NMBs,WFLX,Minamata

Improved,atmospheric,mercury,simulation,using,updated,particle,organic,aerosol,concentrations,gaseous,particulate,forms,divalent,Hg,significantly,impact,spa,tial,distribution,deposition,flux,In,new,nested,grid,GEOS,Chem,model,try,modify,partitioning,tionship,synchronous,hourly,observations,four,sites,China,Observations,oxidized,GOM,bound,PBM,PM2,were,used,derive,empirical,coefficient,function,temperature,OA,under,different,relative,humidity,RH,Results,showed,that,increasing,dominant,process,changed,from,physical,adsorption,chemical,desorption,And,We,thus,improved,simulated,field,by,introducing,intermediate,volatility,semi,volatile,compounds,SVOCs,emission,inventory,into,framework,refining,according,filed,tests,recent,literatures,Finally,normalized,mean,biases,monthly,element,GEM,reduced,explains,observed,decrease,during,useful,tool,evaluate,effectiveness,Convention,Mercury

0.562564