Here aerosol volatility and viscosity at a rural site (Gucheng) and an urban site (Beijing) in North China Plain (NCP) in summer and winter were investigated. Our results showed that organic aerosol (OA) in winter in NCP is more volatile than that in summer due to enhanced primary emissions from coal combustion and biomass burning. We also found that OA existed mainly as solid in winter in Beijing, but as semi-solids in Beijing in summer and Gucheng in winter.
Here aerosol volatility and viscosity at a rural site (Gucheng) and an urban site (Beijing) in...
1State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
2College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
3Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
4Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
5State Key Laboratory of Severe Weather & Key Laboratory for Atmospheric Chemistry, Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences, Beijing, 100081, China
6Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
7Aerodyne Research Inc., Billerica, Massachusetts 01821, USA
8School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
9School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
10School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
11Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
anow at: Earth Sciences Department, Barcelona Supercomputing Center, BSC-CNS, Barcelona 08034, Spain
bnow at: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
1State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
2College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
3Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
4Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
5State Key Laboratory of Severe Weather & Key Laboratory for Atmospheric Chemistry, Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences, Beijing, 100081, China
6Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China
7Aerodyne Research Inc., Billerica, Massachusetts 01821, USA
8School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
9School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
10School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
11Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
anow at: Earth Sciences Department, Barcelona Supercomputing Center, BSC-CNS, Barcelona 08034, Spain
bnow at: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
Received: 22 Oct 2020 – Accepted for review: 04 Dec 2020 – Discussion started: 04 Dec 2020
Abstract. Volatility and viscosity have substantial impacts on gas-particle partitioning, formation and evolution of aerosol, and hence the predictions of aerosol related air quality and climate effects. Here aerosol volatility and viscosity at a rural site (Gucheng) and an urban site (Beijing) in North China Plain (NCP) in summer and winter were investigated by using a thermodenuder coupled with high resolution aerosol mass spectrometer. The effective saturation concentration (C*) of organic aerosol (OA) in summer was smaller than that in winter (0.55 μg m−3 vs. 0.71–0.75 μg m−3), indicating that OA in winter in NCP is more volatile due to enhanced primary emissions from coal combustion and biomass burning. The volatility distributions varied largely different among different OA factors. In particular, we found that hydrocarbon-like OA (HOA) contained more non-volatile compounds compared to coal combustion related OA. The more oxidized oxygenated OA (MO-OOA) showed overall lower volatility than less oxidized OOA (LO-OOA) in both summer and winter, yet the volatility of MO-OOA was found to be relative humidity (RH) dependent showing more volatile properties at higher RH. Our results demonstrated the different composition and chemical formation pathways of MO-OOA under different RH levels. The glass transition temperature (Tg) and viscosity of OA in summer and winter are estimated using the recently developed parameterization formula. Our results showed that the Tg of OA in summer in Beijing (291.5 K) was higher than that in winter (289.7–290.0 K), while it varied greatly among different OA factors. The viscosity suggested that OA existed mainly as solid in winter in Beijing, but as semi-solids in Beijing in summer and Gucheng in winter. These results have important implications that kinetically limited gas-particle partitioning may need to be considered when simulating secondary OA formation in NCP.
Here aerosol volatility and viscosity at a rural site (Gucheng) and an urban site (Beijing) in North China Plain (NCP) in summer and winter were investigated. Our results showed that organic aerosol (OA) in winter in NCP is more volatile than that in summer due to enhanced primary emissions from coal combustion and biomass burning. We also found that OA existed mainly as solid in winter in Beijing, but as semi-solids in Beijing in summer and Gucheng in winter.
Here aerosol volatility and viscosity at a rural site (Gucheng) and an urban site (Beijing) in...
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