Elucidating Secondary Organic Aerosol Processes through High-Resolution Aerosol Mass Spectrometry in Beijing  

作　　者：Weiqi XU Chun CHEN Zhijie LI Zhiqiang ZHANG Yu ZHANG Zifa WANG Yele SUN 

机构地区：[1]Key Laboratory of Atmospheric Environment and Extreme Meteorology,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China [2]State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China [3]College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [4]State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China [5]China Meteorological Administration Training Centre,Beijing 100081,China

出　　处：《Advances in Atmospheric Sciences》2025年第4期670-681,共12页大气科学进展(英文版)

基　　金：supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0760200);the National Natural Science Foundation of China(Grant No.42377101,91744207).

摘　　要：Exploring secondary organic aerosol(SOA)processes is crucial for understanding climate and air pollution in megacities.This study introduces a new method using positive matrix factorization(PMF)to investigate the SOA process by integrating the OA and associated ions previously misidentified as inorganic aerosol in high-resolution aerosol mass spectrometry data.The mass spectra and time series of primary OA(POA)and less oxidized oxygenated OA(OOA)identified by this new method resembled those resolved by traditional PMF.However,more oxidized OOA(MO-OOA)identified by traditional PMF can be further subdivided into multiple OA factors,including nitrogen-enriched OA(ON-OA)and sulfur-enriched OA(OS-OA)in summer,and ON-OA,OS-OA,and OOA in winter.Our findings highlight the significant role of photochemical processes in the formation of OS-OA compared to ON-OA.The compositions of reconstructed MO-OOA varied under different Ox(=O_(3)+NO_(2))and relative humidity conditions,emphasizing the limitations of using a constant mass spectrum.Aged biomass burning OA(BBOA)and coal combustion OA(CCOA),previously misattributed as POA,contributed 9.2%(0.43μg m^(−3))and 7.0%(0.33μg m^(−3))to SOA,respectively.Aged BBOA was more prone to forming OS-OA,whereas ON-OA showed higher correlations with aged CCOA,indicating distinct molecular compositions of SOA from different aged POA sources.Compared to aged BBOA,aged CCOA was more subject to conversion during aqueous phase processing.These results suggest that the variations in mass spectra and compositions need to be considered when simulating SOA processes.

关 键 词：secondary organic aerosol positive matrix factorization aerosol mass spectrometry nitrogen-enriched organic aerosol sulfur-enriched organic aerosol 

分 类 号：X513[环境科学与工程—环境工程]