Contrasting Influence of Nitrogen Oxides on the Cloud Condensation Nuclei Activity of Monoterpene-Derived Secondary Organic Aerosol in Daytime and Nighttime Oxidation

作者：Zhang, Chenqi; Guo, Yindong; Shen, Hongru; Luo, Hao; Pullinen, Iida; Schmitt, Sebastian H. H.; Wang, Mingjin; Fuchs, Hendrik; Kiendler-Scharr, Astrid; Wahner, Andreas; Mentel, Thomas F. F.^*; Zhao, Defeng^*

来源：Geophysical Research Letteres, 2023, 50(4): e2022GL102110.

DOI：10.1029/2022GL102110

• cloud condensation nuclei
• secondary organic aerosol
• monoterpene
• nitrogen oxides
• NO3 radical
• OH oxidation

Anthropogenic nitrogen oxides may influence the cloud condensation nuclei (CCN) activity of biogenic secondary organic aerosols (SOA) in both daytime photooxidation and nighttime NO3 oxidation, which has significant implications for the climatic impact of SOA. We investigated the influence of NOx on the CCN activity of monoterpene-derived SOA in OH oxidation and in NO3 oxidation. In OH oxidation, NOx had little influence on the hygroscopic parameter kappa of organic aerosol (kappa(Org)), which was attributed to the minor fraction of organic nitrates (ON) in SOA (<24%), resulted from the low branching ratio of RO2 + NO to form ON. In contrast, in NO3 oxidation kappa(Org) was much reduced compared to OH/O-3 oxidation due to a dominant fraction of ON. We report kappa of MT-derived ON formed in photo-oxidation and NO3 oxidation (0.029-0.052) for the first time to our knowledge, which may be used to improve model simulations of CCN concentrations.

• 单位
  复旦大学