Submicron aerosol particles （with aerody- namic diameters less than 1 pm, PM1） were sampled and measured in Heshan, an urban outflow site of Guangzhou megacity in Pearl River Delta in South China, using an Aerodyne ...Submicron aerosol particles （with aerody- namic diameters less than 1 pm, PM1） were sampled and measured in Heshan, an urban outflow site of Guangzhou megacity in Pearl River Delta in South China, using an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer （HR-ToF-AMS） in November 2010 during 2010 Guangzhou Asian Games. The mean PM~ mass concentration measured was 47.9 ± 17.0 μg.m3 during the campaign, with organic aerosol （OA） and sulfate being the two dominant species, accounting for 36.3% and 20.9% of the total mass, respectively, followed by black carbon （17.1%, measured by an aethalometer）, nitrate （12.9%）, ammonium （9.6%） and chloride （3.1%）. The average size distributions of the species （except black carbon） were dominated by an accumulation mode peaking at -550 nm. Calculations based on high-resolution organic mass spectrum showed that, C, H, O and N on average contributed 58.1%, 7.3%, 30.7%, and 3.9% to the total organic mass, respectively. The average ratio of organic mass over organic carbon mass （OM/OC） was 1.73 ± 0.08. Four components of OA were identified by the Positive Matrix Factorization （PMF） analysis, including a hydro- carbon-like （HOA）, a biomass burning （BBOA） and two oxygenated （SV-OOA and LV-OOA） organic aerosol components, which on average accounted for 18.0%, 14.3%, 28.8% and 38.9% of the total organic mass, respectively.展开更多
A thorough understanding of chemical composition,particle pH,and pollutant emissions is essential to address the climate and human health effects of atmospheric particles.In this study,we used a High-Resolution Time-o...A thorough understanding of chemical composition,particle pH,and pollutant emissions is essential to address the climate and human health effects of atmospheric particles.In this study,we used a High-Resolution Time-of-Flight Aerosol Mass Spectrometer(HR-ToF-AMS)and Scanning Mobility Particle Sizer(SMPS)to characterize the composition of submicron particles.Moreover,we applied the ISORROPIA-II model to analyze the particle acidity effect on the compositional characterization of submicron particles from December 22,2016 to January 7,2017 in Albany,New York,USA.The results indicated that aerosols with mobility diameter from SMPS in the range 200–400 nm were the main contributors to the mass during the measurement period.The dominance of organics(47%)and sulfate(16%)was similar to previous observations in the eastern United States in Winter 2015,while the fraction of nitrate(23%)was much higher.Moreover,nitrate could easily form at colder temperatures and lower RH levels even when there were more acidic particle periods during the measurement period in Albany.The ISORROPIA-II model indicated that there were more acidic particles,which was estimated using pH values.Lower temperature conditions tended to favor nitrate formation.The nitrate concentration exceeded that of sulfate in the measurement period,even though the SO2and NOxemissions were similar.The organics in submicron particles were strongly influenced by the local emissions in winter.However,the inorganic compounds in submicron particles could be derived from regional transport as their pollution sources originated from different directions.This may help strategize emission reductions in the future.展开更多
文摘Submicron aerosol particles （with aerody- namic diameters less than 1 pm, PM1） were sampled and measured in Heshan, an urban outflow site of Guangzhou megacity in Pearl River Delta in South China, using an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer （HR-ToF-AMS） in November 2010 during 2010 Guangzhou Asian Games. The mean PM~ mass concentration measured was 47.9 ± 17.0 μg.m3 during the campaign, with organic aerosol （OA） and sulfate being the two dominant species, accounting for 36.3% and 20.9% of the total mass, respectively, followed by black carbon （17.1%, measured by an aethalometer）, nitrate （12.9%）, ammonium （9.6%） and chloride （3.1%）. The average size distributions of the species （except black carbon） were dominated by an accumulation mode peaking at -550 nm. Calculations based on high-resolution organic mass spectrum showed that, C, H, O and N on average contributed 58.1%, 7.3%, 30.7%, and 3.9% to the total organic mass, respectively. The average ratio of organic mass over organic carbon mass （OM/OC） was 1.73 ± 0.08. Four components of OA were identified by the Positive Matrix Factorization （PMF） analysis, including a hydro- carbon-like （HOA）, a biomass burning （BBOA） and two oxygenated （SV-OOA and LV-OOA） organic aerosol components, which on average accounted for 18.0%, 14.3%, 28.8% and 38.9% of the total organic mass, respectively.
基金supported by the National Natural Science Foundation of China(Nos.91544218 and 41905028)the Science and Technological Fund of Anhui Province for Outstanding Youth(No.1808085J19)the China Scholarship Council。
文摘A thorough understanding of chemical composition,particle pH,and pollutant emissions is essential to address the climate and human health effects of atmospheric particles.In this study,we used a High-Resolution Time-of-Flight Aerosol Mass Spectrometer(HR-ToF-AMS)and Scanning Mobility Particle Sizer(SMPS)to characterize the composition of submicron particles.Moreover,we applied the ISORROPIA-II model to analyze the particle acidity effect on the compositional characterization of submicron particles from December 22,2016 to January 7,2017 in Albany,New York,USA.The results indicated that aerosols with mobility diameter from SMPS in the range 200–400 nm were the main contributors to the mass during the measurement period.The dominance of organics(47%)and sulfate(16%)was similar to previous observations in the eastern United States in Winter 2015,while the fraction of nitrate(23%)was much higher.Moreover,nitrate could easily form at colder temperatures and lower RH levels even when there were more acidic particle periods during the measurement period in Albany.The ISORROPIA-II model indicated that there were more acidic particles,which was estimated using pH values.Lower temperature conditions tended to favor nitrate formation.The nitrate concentration exceeded that of sulfate in the measurement period,even though the SO2and NOxemissions were similar.The organics in submicron particles were strongly influenced by the local emissions in winter.However,the inorganic compounds in submicron particles could be derived from regional transport as their pollution sources originated from different directions.This may help strategize emission reductions in the future.
