Observational Study of Ground-Level Ozone in the Desert Atmosphere.

Arid lands such as deserts cover more than 35% of the Earth's land surface. Concerns regarding ground-level O 3 pollution have been widely addressed in many regions in China, but the behavior of the O 3 cycles in the desert atmosphere remains poorly understood. An 8-year observation was conducted to investigate the long-term temporal O 3 variations in the atmosphere of the Taklimakan Desert, western China. The results showed that the diurnal and seasonal variations of O 3 were mainly influenced by natural processes such as temperature, leading to a different temporal pattern compared with other Chinese regions under the intensive influence of anthropogenic activities. Moreover, the long-term pattern indicates that there exists decoupling trends of O 3 variations between our study site (i.e., decreasing trend) and the developed regions in China (i.e., increasing trend). Knowledge of the temporal O 3 patterns could therefore provide crucial insights for future effective O 3 control strategies in China.