Characteristics and Causes of Ozone Pollution in 16 Cities of Yunnan Plateau

In order to study the characteristics and causes of ozone (O3) pollution in 16 cities Yunnan Plateau, methods COD, backward trajectory potential source contribution function (PSCF) were used analyze O3 concentrations from 2015 2020 all state-controlled environmental monitoring stations Yunnan. The results show that gradually increased 2019, concentration was lowest due COVID-19 pandemic. peak appears spring. daily change trend is a typical single shape, value around 8: 00, highest between 15:00 16:00. High are Zhaotong Kunming northeastern Yunnan, while low mainly occur southwest northwest border areas. Temperature relative humidity two meteorological parameters have significant effect on concentration. has best correlation with winter, better autumn winter than spring summer. Finally, analysis showed local precursor emission sources long-distance transmission South Southeast Asia constituted major contributions