As Volatile Organic Compounds(VOCs)are one of the precursors of ozone,their distribution and variable concentrations are highly related to local ozone pollution control.In this study,we obtained vertical profiles of V...As Volatile Organic Compounds(VOCs)are one of the precursors of ozone,their distribution and variable concentrations are highly related to local ozone pollution control.In this study,we obtained vertical profiles of VOCs in Shanghai’s Jinshan district on 8 September and 9 September in 2016 to investigate their distribution and impact on local atmospheric oxidation in the near surface layer.Vertical samples were collected from heights between 50 m and 400 m by summa canisters using an unmanned aerial vehicle(UAV).Concentrations of VOCs(VOCs refers to the 52 species measured in this study)varied minimally below 200 m,and decreased by 21.2%from 100 m to 400 m.The concentrations of VOCs above 200 m decreased significantly in comparison to those below 200 m.The proportions of alkanes and aromatics increased from 55.2%and 30.5%to 57.3%and 33.0%,respectively.Additionally,the proportion of alkenes decreased from 13.2%to 8.4%.Toluene and m/p-xylene were the key species in the formation of SOA and ozone.Principal component analysis(PCA)revealed that the VOCs measured in this study mainly originated from industrial emissions.展开更多
Ozone is a crucial air pollutant that damages human health and vegetation.As it is related to the photo-oxidation of the nitrogen oxides and volatile organic compounds,the summertime reduction of these precursors is t...Ozone is a crucial air pollutant that damages human health and vegetation.As it is related to the photo-oxidation of the nitrogen oxides and volatile organic compounds,the summertime reduction of these precursors is the primary focus of current ozone mitigation strategies.During ozone pollution episodes in eastern China,an observed accumulation of daily total oxidants(O_(x)=NO_(2)+O_(3))in cool seasons(spring and autumn:60 ppb and winter 40 ppb)is comparable to that in summer(60 ppb),indicating fast photochemical production of secondary pollutants including ozone over the year.Unrecognized fast radical primary productions are found to counteract the increased termination of hydroxyl radical and unfavorable meteorological conditions to maintain the rapid total oxidant formations in cool seasons.Elucidating and regulating the primary radical sources may be critical for the secondary air pollution control in cool seasons.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.41830106,21607104)the National Key Research and Development Plan(Grant Nos.2017YFC0210004,2018YFC0213801)+1 种基金the Shanghai Science and Technology Commission of Shanghai Municipality(18QA 403600)the Shanghai Environmental Protection Bureau(2017-2).
文摘As Volatile Organic Compounds(VOCs)are one of the precursors of ozone,their distribution and variable concentrations are highly related to local ozone pollution control.In this study,we obtained vertical profiles of VOCs in Shanghai’s Jinshan district on 8 September and 9 September in 2016 to investigate their distribution and impact on local atmospheric oxidation in the near surface layer.Vertical samples were collected from heights between 50 m and 400 m by summa canisters using an unmanned aerial vehicle(UAV).Concentrations of VOCs(VOCs refers to the 52 species measured in this study)varied minimally below 200 m,and decreased by 21.2%from 100 m to 400 m.The concentrations of VOCs above 200 m decreased significantly in comparison to those below 200 m.The proportions of alkanes and aromatics increased from 55.2%and 30.5%to 57.3%and 33.0%,respectively.Additionally,the proportion of alkenes decreased from 13.2%to 8.4%.Toluene and m/p-xylene were the key species in the formation of SOA and ozone.Principal component analysis(PCA)revealed that the VOCs measured in this study mainly originated from industrial emissions.
基金supported by the Natural Science Foundation of Beijing Municipality(JQ19031)the National Natural Science Foundation of China(21976006,21522701,and 91544225)+1 种基金the National Research Program for Key Issue in Air Pollution Control(2019YFC0214800 and 2018YFC0213800)the Science and Technology Commission of the Shanghai Municipality(18QA1403600).
文摘Ozone is a crucial air pollutant that damages human health and vegetation.As it is related to the photo-oxidation of the nitrogen oxides and volatile organic compounds,the summertime reduction of these precursors is the primary focus of current ozone mitigation strategies.During ozone pollution episodes in eastern China,an observed accumulation of daily total oxidants(O_(x)=NO_(2)+O_(3))in cool seasons(spring and autumn:60 ppb and winter 40 ppb)is comparable to that in summer(60 ppb),indicating fast photochemical production of secondary pollutants including ozone over the year.Unrecognized fast radical primary productions are found to counteract the increased termination of hydroxyl radical and unfavorable meteorological conditions to maintain the rapid total oxidant formations in cool seasons.Elucidating and regulating the primary radical sources may be critical for the secondary air pollution control in cool seasons.
