Determining diurnal fossil fuel CO2 and biological CO2 by Δ14CO2 observation on certain summer and winter days at Chinese background sites

Zhenchuan Niu; Weijian Zhou; Xue Feng; Yaoyao Hou; Ning Chen; Hua Du; Shugang Wu; Yunchong Fu; Xuefeng Lu; Peng Cheng; Xiaohu Xiong; Peng Wang; Jianqiong Wang; Jie Yao; Jie Zhou; Ming Li

doi:10.1016/j.scitotenv.2020.136864

Determining diurnal fossil fuel CO₂ and biological CO₂ by Δ¹⁴CO₂ observation on certain summer and winter days at Chinese background sites

Sci Total Environ. 2020 May 20:718:136864. doi: 10.1016/j.scitotenv.2020.136864. Epub 2020 Jan 21.

Authors

Zhenchuan Niu¹, Weijian Zhou², Xue Feng³, Yaoyao Hou⁴, Ning Chen⁴, Hua Du⁴, Shugang Wu⁴, Yunchong Fu⁴, Xuefeng Lu⁴, Peng Cheng⁴, Xiaohu Xiong⁴, Peng Wang⁴, Jianqiong Wang⁵, Jie Yao⁶, Jie Zhou⁴, Ming Li⁴

Affiliations

¹ State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; CAS Center for Excellence in Quaternary Science and Global Change, China; Open Studio for Oceanic-Continental Climate and Environment Changes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China; Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Joint Xi'an AMS Center between IEECAS and Xi'an Jiaotong University, Xi'an, China.
² State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; CAS Center for Excellence in Quaternary Science and Global Change, China; Open Studio for Oceanic-Continental Climate and Environment Changes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China; Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Joint Xi'an AMS Center between IEECAS and Xi'an Jiaotong University, Xi'an, China. Electronic address: weijian@loess.llqg.ac.cn.
³ State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an, China; Xi'an Institute for Innovative Earth Environment Research, Xi'an, China.
⁴ State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; Shaanxi Provincial Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Joint Xi'an AMS Center between IEECAS and Xi'an Jiaotong University, Xi'an, China.
⁵ Waliguan Global Background Station, Qinghai, China.
⁶ Lin'an Regional Background Station, Lin'an, Zhejiang, China.

PMID: 32105930
DOI: 10.1016/j.scitotenv.2020.136864

Abstract

Diurnal atmospheric Δ¹⁴CO₂ was measured on two consecutive days in summer and winter, 2016 at Shangdianzi, Lin'an and Luhuitou regional background sites, and at Waliguan global background site in China. The objectives of this study were to determine diurnal fossil fuel CO₂ (CO_2ff) and biological CO₂ (CO_2bio) concentrations and to ascertain the factors influencing them. Evident CO_2ff inputs (0-33.0 ± 1.4 ppm) were found, with some small morning and afternoon rush hour signals. Particularly, the long-range transport of air masses influenced the seasonal differences and rapid diurnal variations in CO_2ff. Diurnal CO_2bio showed violent variations (-20.9-113.3 ppm), with high values at night and low or negative values during the daytime. Diurnal CO_2bio variations resulted from the tradeoffs between photosynthetic CO₂ uptake and biological respiration CO₂ emission as well as atmospheric boundary layer heights variations. These results might help to understand the roles of fossil fuel sources and biological sources on atmospheric CO₂ diurnal variations at Chinese background sites.

Keywords: Background sites; Biological sources; Diurnal atmospheric CO(2); Fossil fuel sources; Long-range transport; Radiocarbon.