Tower-based Measurement of Volatile Organic Compounds and Green House Gases

In recent years, ambient ozone concentrations exhibit persistent rising trends in China, hinting the importance of secondary pollution abatement for next decades. However, the vertical structure of ozone and its precursors as well as formation sensitivity in the near-surface atmosphere. And central government has been strongly pushing the synergetic control of air pollution and green-house gases. We developed gradient measurements for ozone, NOx and VOCs together with flux measurements for methane in the near-surface atmosphere (0-500 m), trying to explore the approach for a better understanding of ozone chemistry and CH₄ sources. The measured vertical distribution and evolution patterns of ozone and its precursors were used by box model to interpret the vertical distribution of ozone formation sensitivity, and to quantitatively evaluate the impacts and contribution of vertical transport processes on change in surface ozone levels. Meanwhile, CH₄ flux was measured in Beijing by using the eddy covariance in the tower-based campaign. The inter-Comparison with domestic and international gridded inventories (namely PKU-CH₄-V2 and EDGAR-V8) suggested a significant underestimation of CH₄ emissions from natural gas usage.

Keywords: Ozone; Methane; Volatile Organic Compounds; Vertical Observation; Natural Gas Leakage