G01_P04

Vertical dynamics of particulate carbon sources during a haze pollution episode using the measurements of dual-carbon isotopes

Jiang F^1,2, Liu J¹, Strähl J², Szidat S², Wang Y¹, Cheng Z^3,7, Zhu S^3,7, Ding P^4,7, Cao F⁵, Zhang Y⁵, Zhou S⁶, Zheng J¹, Li J^3,7, Zhang G^3,7

¹Institute for Environmental and Climate Research, Jinan University, Guangzhou, China, ²Department of Chemistry, Biochemistry and Pharmaceutical Sciences and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland, ³State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China, ⁴State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China, ⁵Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing, China, ⁶School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou, China, ⁷CAS Center for Excellence in Deep Earth Science, Guangzhou, China

Carbonaceous aerosols, an important component of PM₂.₅, have been identified as the critical trigger influencing the formation and evolution of severe atmospheric haze pollution in many regions around the world. Stable carbon isotope (¹³C) and radiocarbon (¹⁴C) measurements are powerful tools for identifying and quantifying the relative contributions of key sources to haze pollution. In this study, we investigated the dynamic changes of the signals of ¹³C and ¹⁴C in PM₂.₅ samples collected at different heights of the Canton Tower in Guangzhou in South China in the 2020/2021 winter season, during which a severe haze episode occurred. The ¹⁴C measurements showed that there is an obvious difference in the sources of total carbon aerosol among different heights. In addition, we found that the ¹⁴C signals varied dramatically during this haze episode, suggesting that the sources of particulate carbon were constantly changing during the formation and evolution of the atmospheric haze pollution. To further investigate the sources and formation mechanisms of this haze event, we will 1) refine the source information based on the measurements of ¹³C and ¹⁴C in subfractions of total carbon; 2) find out the key source and mechanism that triggered this haze pollution.