N<sub>2</sub>O<sub>5</sub> uptake onto saline mineral dust: a potential missing source of tropospheric ClNO<sub>2</sub> in inland China

Abstract. Nitryl chloride (ClNO2), an important precursor of Cl atoms, significantly affects atmospheric oxidation capacity and O3 formation. However, sources ClNO2 in inland China have not been fully elucidated. In this work, laboratory experiments were conducted to investigate heterogeneous reactions N2O5 with eight saline mineral dust samples collected from different regions China, substantial formation was observed these reactions. yields, ?(ClNO2), showed large variations (ranging <0.05 ?0.77) for samples, depending on mass fractions particulate chloride. addition, ?(ClNO2) could increase, decrease or show insignificant change when relative humidity (RH) increased 18 % 75 %. We further found that current parameterizations overestimated uptake onto dust. assuming a uniform value 0.10 dust, we used 3-D chemical transport model assess the impact reaction tropospheric weekly mean nighttime maximum mixing ratios by up 85 pptv during severe event May 2017. Overall, our work be source China.