The characteristic of atmospheric CO2 and CO concentrations based on aircraft observation over Tangshan

During November 2018 and March 2019, a high-precision greenhouse gas analyzer and related auxiliary equipment were carried out by Yun-12aircraft to measure the CO2 and CO concentration over Tangshan City from 200m to 4600m a.s.l to study the spatial and temporal distribution of CO2 and CO concentrations over the city. During this observation period, six vertical profiles of CO2 and CO concentration were obtained. The results showed that the CO2 concentration varied from 406×10-6 to 453×10-6, while the CO concentration varied from 27×10-9 to 1135×10-9. For night observations when there were stable mixed layer, both CO2 and CO concentrations reached their maximums at the top of the mixed layer. However, during daytime when there were no obvious mixed layer, both CO2 and CO concentrations decreased with height. Significant correlations between CO2 and CO concentrations were found when the averaged wind speeds were less than that of moderate breeze, and the CO2/CO ratios ranged from 32.2 to 43.9. In the case study on February 2019, both CO2 and CO concentrations elevated when the air mass passed over Tangshan, which indicated the city might be a carbon source in this situation, CO2 flux can be further quantified by mass balance approach or inverse modelling. © 2020, Editorial Board of China Environmental Science. All right reserved.