Simulation of organic nitrates in Pearl River Delta in 2006 and the chemical impact on ozone production

Organic nitrates are secondary atmospheric pollutants that play a key role in ozone and aerosol production. This study focused on the simulation of organic nitrates through a box model coupled with RACM2 (Regional Atmospheric Chemistry Mechanism, version 2), based on data from the PRIDE-PRD2006 campaign in Backgarden, China. Our study found that an overestimation of organic nitrate production rate was generated by the model. Furthermore, the effective production ratio (α_eff) of organic nitrates was around 0.033 after optimizing its chemical production module. The chemical impacts of organic nitrates on ozone production were related to VOC-OH reactivity and α_eff. We found that VOC-OH reactivity was positively related to α_eff, resulting in the suppression of ozone production caused by organic nitrates, which showed that P(O _x =O₃+NO₂) increased initially and subsequently decreased with VOC-OH reactivity. These results highlight the importance of organic nitrate’s impact on ozone production in strategies to control ozone pollution, specifically regarding the reduction of low-molecular-weight VOCs in the Pearl River Delta.