EGU General Assembly 2020
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the Creative Commons Attribution 4.0 License.

Effect of potential HONO sources on ROx budgets and SOA and PAN formation in North China in winter

Jingwei Zhang and Junling An
Jingwei Zhang and Junling An
  • Institute of Atmospheric Physics (IAP), Chinese Academy of Science, State Key Laboratory of Atmospheric Boundary Layer, Beijing, China (

Recent wintertime observations in north China found high concentrations of nitrous acid (HONO), secondary organic aerosols (SOA) and peroxyacetyl nitrate (PAN), especially during heavy haze periods, indicating stronger atmospheric oxidation capacity in winter haze days. Researchers speculated that HONO formation was enhanced in haze days through NO2 heterogeneous reaction on aerosol surfaces, and high concentrations of HONO during daytime further improved SOA and PAN formation.

In this study, the WRF-Chem model updated with six potential HONO sources was used to quantify the impacts of potential HONO sources on the production and loss rates of ROx ( OH+HO2+RO2) radicals, and on the concentrations of SOA and PAN in the Beijing-Tianjin-Hebei (BTH) region of China during wintertime of 2017. HONO simulations were greatly improved after considering the six potential sources, NO2 heterogeneous reactions were the main sources of HONO. HONO photolysis was the key precursors of primary OH while the contribution of O3 photolysis to OH could be neglected, the potential HONO sources remarkably accelerated ROx cycles, significantly improved SOA and PAN simulations, especially in heavy polluted periods. The above results suggest that the potential HONO sources should be considered in regional and global chemical transport models when conducting relevant studies.

How to cite: Zhang, J. and An, J.: Effect of potential HONO sources on ROx budgets and SOA and PAN formation in North China in winter, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1438,, 2019


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