Xu, W. Q., C. Chen, Z. J. Li, Z. Q. Zhang, Y. Zhang, Z. F. Wang, and Y. L. Sun, 2025: Elucidating secondary organic aerosol processes through high-resolution aerosol mass spectrometry in Beijing. Adv. Atmos. Sci., https://doi.org/10.1007/s00376-024-4207-6.
Citation: Xu, W. Q., C. Chen, Z. J. Li, Z. Q. Zhang, Y. Zhang, Z. F. Wang, and Y. L. Sun, 2025: Elucidating secondary organic aerosol processes through high-resolution aerosol mass spectrometry in Beijing. Adv. Atmos. Sci., https://doi.org/10.1007/s00376-024-4207-6.

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

  • 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 (= O3 + NO2) 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% (0.43 μg m−3) and 7.0% (0.33 μg 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.
  • loading

Catalog

    Turn off MathJax
    Article Contents

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return