The nitrate radical(NO3)and dinitrogen pentoxide(N2.5)play an important role in the nocturnal atmosphere chemistry.Observations of N03 radicals and N2 O5 were performed in a semirural ground site at Tai’Zhou in pollu...The nitrate radical(NO3)and dinitrogen pentoxide(N2.5)play an important role in the nocturnal atmosphere chemistry.Observations of N03 radicals and N2 O5 were performed in a semirural ground site at Tai’Zhou in polluted southern China using cavity ring down spectroscopy(CRDS)from 23 May to 15 June 2018.The observed N03 and N2 O5 concentrations were relatively low,with 1 min average value of 4.4±2.2 and 26.0±35.7 pptV,respectively.The N2 O5 uptake coefficient was determined to be from 0.027 to 0.107 based on steady state lifetime method.Fast N2 O5 hydrolysis was the largest contributor to the loss of NO3 and contributed to substantial nitrate formation,with an average value of 14.83±6.01μg/m3.Further analysis shows that the N2 O5 heterogeneous reactions dominated the nocturnal NOx loss and the nocturnal NOx loss rate is 0.14±0.02 over this region.展开更多
The heterogeneous hydrolysis of dinitrogen pentoxide(N2O5)plays an important role in regulating NOx.The N2O5 uptake coefficient,γ(N2O5),was determined using an iterative box model that was constrained to observationa...The heterogeneous hydrolysis of dinitrogen pentoxide(N2O5)plays an important role in regulating NOx.The N2O5 uptake coefficient,γ(N2O5),was determined using an iterative box model that was constrained to observational data obtained in suburban Beijing from February to March 2016.The box model determined 2289 individualγ(N2O5)values that varied from<0.001 to 0.02 with an average value of 0.0046±0.0039(and a median value of 0.0032).We found the derived winterγ(N2O5)values in Beijing were relatively low as compared to values reported in previous field studies conducted during winter in Hong Kong(average value of 0.014)and the eastern U.S.coast(median value of 0.0143).In our study,field evidence of the suppression ofγ(N2O5)values due to pNO3-content,organics and the enhancement by aerosol liquid water content(ALWC)is in line with previous laboratory study results.Low ALWC,high pNO3-content,and particle morphology(inorganic core with an organic shell)accounted for the lowγ(N2O5)values in the North China Plain(NCP)during wintertime.The field-derivedγ(N2O5)values are well reproduced by a revised parameterization method,which includes the aerosol size distribution,ALWC,nitrate and organic coating,suggesting the feasibility of comprehensive parameterization in the NCP during wintertime.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41530644,51904009,61805257 and 41905130)Open Fund of Key Laboratory of Environmental Optics and Technology,Chinese Academy of Sciences(No.2005DP173065-2019-06)+1 种基金the Nature Science Research Project of Anhui province(No.1908085QD159)the Outstanding Young Talents Program of Anhui University of China(No.gxyq2019022)
文摘The nitrate radical(NO3)and dinitrogen pentoxide(N2.5)play an important role in the nocturnal atmosphere chemistry.Observations of N03 radicals and N2 O5 were performed in a semirural ground site at Tai’Zhou in polluted southern China using cavity ring down spectroscopy(CRDS)from 23 May to 15 June 2018.The observed N03 and N2 O5 concentrations were relatively low,with 1 min average value of 4.4±2.2 and 26.0±35.7 pptV,respectively.The N2 O5 uptake coefficient was determined to be from 0.027 to 0.107 based on steady state lifetime method.Fast N2 O5 hydrolysis was the largest contributor to the loss of NO3 and contributed to substantial nitrate formation,with an average value of 14.83±6.01μg/m3.Further analysis shows that the N2 O5 heterogeneous reactions dominated the nocturnal NOx loss and the nocturnal NOx loss rate is 0.14±0.02 over this region.
基金supported by the National Natural Science Foundation of China(21976006,41907185,91844301,91544225)Beijing Natural Science Foundation,China(JQ19031)China Postdoctoral Science Foundation(2018M641095,2019T120023)。
文摘The heterogeneous hydrolysis of dinitrogen pentoxide(N2O5)plays an important role in regulating NOx.The N2O5 uptake coefficient,γ(N2O5),was determined using an iterative box model that was constrained to observational data obtained in suburban Beijing from February to March 2016.The box model determined 2289 individualγ(N2O5)values that varied from<0.001 to 0.02 with an average value of 0.0046±0.0039(and a median value of 0.0032).We found the derived winterγ(N2O5)values in Beijing were relatively low as compared to values reported in previous field studies conducted during winter in Hong Kong(average value of 0.014)and the eastern U.S.coast(median value of 0.0143).In our study,field evidence of the suppression ofγ(N2O5)values due to pNO3-content,organics and the enhancement by aerosol liquid water content(ALWC)is in line with previous laboratory study results.Low ALWC,high pNO3-content,and particle morphology(inorganic core with an organic shell)accounted for the lowγ(N2O5)values in the North China Plain(NCP)during wintertime.The field-derivedγ(N2O5)values are well reproduced by a revised parameterization method,which includes the aerosol size distribution,ALWC,nitrate and organic coating,suggesting the feasibility of comprehensive parameterization in the NCP during wintertime.
