Direct measurement of N 2 O 5 heterogeneous uptake coefficients on atmospheric aerosols in southwestern China and evaluation of current parameterizations

作者：Jiayin Li, Tianyu Zhai, Xiaorui Chen, Haichao Wang, Shuyang Xie, Shiyi Chen, Chunmeng Li, Yuanjun Gong, Huabin Dong, Keding Lu · 发表于：Atmospheric chemistry and physics · 年份：2025 · DOI：10.5194/acp-25-6395-2025 · 被引用次数：8 · 研究领域：Atmospheric chemistry and aerosols、Atmospheric and Environmental Gas Dynamics、Atmospheric Ozone and Climate

Abstract. The heterogeneous hydrolysis of dinitrogen pentoxide (N2O5) is a critical process in assessing NOx fate and secondary pollutant formation. However, accurate quantification of the N2O5 uptake coefficient (γ (N2O5)) in ambient conditions is a challenging problem that can cause unpredictable uncertainties in the predictions of air quality models. Here, the γ (N2O5) values were directly measured using an improved in situ aerosol flow tube system at a site located in a highland region in southwestern China to investigate influencing factors and the performance of current γ (N2O5) parameterizations under this typical environmental condition. The nocturnal mean γ (N2O5) value ranged from 0.0018 to 0.12 with an average of 0.023±0.021. The relationship between the measured γ (N2O5) and impacting factors was consistent with previous laboratory results, except for aerosol chloride. The aerosol water significantly promoted N2O5 uptake, while particulate organics and nitrate showed suppression effects. We found that several parameterizations can capture the median of measured values, whereas none of the 10 parameterizations were able to reproduce the variabilities and showed poor correlations (R2=0.00–0.09). Elevated biases of predictions specifically occurred at high aerosol liquid water content (ALWC) (> 35 M) and low ALWC (< 25 M) levels with an underestimation of −37 % to −1 % and an overestimation of 34 % to 189 %, respectively. Such differences between the measured a...