Articles | Volume 26, issue 3
https://doi.org/10.5194/acp-26-1795-2026
https://doi.org/10.5194/acp-26-1795-2026
Research article
 | 
04 Feb 2026
Research article |  | 04 Feb 2026

Driving factors for the activity coefficient of atmospheric ammonium nitrate: discrepancies among thermodynamic models and impact on nitrate pollutions

Ruilin Wan, Guangjie Zheng, Yuyang Li, Xiaolin Duan, Jingkun Jiang, and Kebin He

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Cited articles

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Short summary
Semi-volatile NH4NO3 is a major component of atmospheric aerosols, and the activity coefficient of NH4NO3 is a key parameter in its estimations. Here we show different thermodynamic models differed in the NH4NO3 non-ideality representations, resulting in discrepancies in nitrate gas–particle partitioning predictions. The driving factors of chemical profiles and meteorological conditions are also investigated. This discrepancy can be an important source of uncertainty in air quality predictions.
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