Quantifying fossil fuel CO2 (CO2ff) in the atmosphere provides a benchmark method to monitor anthropogenic carbon emissions. Radiocarbon (14C) in atmospheric CO2ff has been widely studied using the 14C in plants to document regional CO2ff patterns. However, annual CO2ff variations, reflecting spatial distributions based on plant samples, are still scarce. In this paper, the spatial distribution and temporal CO2ff changes in the Guanzhong Basin is established using Δ14C measurements from maize leaves collected in 2011 and 2012. With regard to spatial distribution, samples collected around Xi'an City showed lower Δ14C values (more CO2ff), while sites located near the perimeter of the basin showed higher Δ14C values (less CO2ff). This is likely due to the concentration of anthropogenic activities in the center of the Guanzhong Basin. The observed CO2ff mole fractions generally matched with PKU CO2 inventory and the ODIAC CO2 inventory data in the spatial distribution trend. However, it seems that thermal power plants were not well captured by the PKU CO2 inventory. Our results provide useful information for the improvement of the inventory and verification of regional carbon cycle models.
Keywords: (14)C; Fossil fuel CO(2); Guanzhong basin; Maize leaves; Spatial distribution.
Copyright © 2022 Elsevier Ltd. All rights reserved.