Heterogeneous sulphate formation in the aerosol, the cloud and the frost
- 1Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, China
- 2Leibniz Institute for Tropospheric Research (TROPOS), Atmospheric Chemistry Department, Permoserstr. 15, D-04318, Leipzig, Germany
The rapid formation of sulphate is the main driving force behind the explosive growth of PM2.5 in China. Our comprehensive study, combined with field observations, laboratory simulations and modelling, indicated that high concentration of hydroperoxide (H2O2) from heterogeneous reactions significantly promoted sulphate formation in winter north China. Unexpectedly, during the same campaign, a high proportion of sulphate has been observed in the frost. The chemical composition of the frost appeared to be independent of that of PM2.5. These findings can be important for the removal rate of SO2 in the atmosphere and for the occult deposition of sulphate.
Also, we have investigated the contribution of oxidation channels to sulphate formation in the cloud at the summit of Mt. Tai (1545 m) in summer. Our results suggested that dissolved ozone is the dominant oxidant for the oxidation of S(IV), especially when the pH of the cloud water is less acidic (> 5.5). In recent years, with the increase of ozone concentration in China, the sulphate formation by ozone in the cloud will continue to be pronounced.
References:
Zhu, C., Li, J.R., Chen, H., Cheng, T.T., Wen, L., Herrmann, H., Xiao, H., Chen, J.M., 2020. Inorganic composition and occult deposition of frost collected under severe polluted area in winter in the North China Plain. Science of the Total Environment 722.
Li, J.R., Zhu, C., Chen, H., Zhao, D.F., Xue, L.K., Wang, X.F., Li, H.Y., Liu, P.F., Liu, J.F., Zhang, C.L., Mu, Y.J., Zhang, W.J., Zhang, L.M., Herrmann, H., Li, K., Liu, M., Chen, J.M., 2020. The evolution of cloud and aerosol microphysics at the summit of Mt. Tai, China. Atmospheric Chemistry and Physics 20, 13735-13751.
How to cite: Chen, H., Li, J., Zhu, C., Herrmann, H., and Chen, J.: Heterogeneous sulphate formation in the aerosol, the cloud and the frost, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4039, https://doi.org/10.5194/egusphere-egu21-4039, 2021.
