Implications for ozone control by understanding the survivor bias in observed ozone-volatile organic compounds system
Zhenyu Wang, Zongbo Shi, Feng Wang, Weiqing Liang, Guoliang Shi, Weichao Wang, Da Chen, Danni Liang, Yinchang Feng, Armistead G. Russell
Abstract
Abstract Tropospheric ozone (O 3 ) affects Earth’s climate and human health. Volatile organic compounds (VOCs), major contributors to O 3 formation, are of particular interest. Generally, the measured concentrations of VOCs (M-VOCs) and O 3 show nonlinear or even opposite time serial-trend. We attributed the phenomenon to survivor bias: lack of insight of the photochemically consumed VOCs (C-VOCs) which emitted from sources to ambient and devote to forming O 3 , while excessive concern on the measured VOCs (M-VOCs) at observation site. Both observational and model results provide evidence that C-VOCs are the key to O 3 formation. We proposed an improved model to quantify the source contributions of C-VOCs (biogenic emissions, gasoline evaporation, industry, etc.) and their impacts on the formation of O 3 , successfully avoiding the misidentification of dominant VOCs sources originated from the survivor bias in observational data. The survivor bias found in this study highlights that focusing of M-VOCs directly is insufficient and demonstrates the necessity of capture the sources of C-VOCs which contribute to O 3 formation.