Estimating ground-level CH₄ concentrations inferred from Sentinel-5P

Improved Gaussian regression model for retrieving ground methane levels by considering vertical profile features

“…Therefore, the atmospheric methane concentration and altitude data must be accurately fitted by a methane profile function to obtain an accurate relationship between the methane concentration at a given altitude and the methane concentration in the atmospheric column. Gaussian functions have been used in previous studies to fit the atmospheric methane profile (Qin et al, 2023). As in formula (2-5), in this study, we compared the fitting of Gaussian functions, multinomial Gaussian functions, smooth curve fitting, and linear interpolation fitting, as shown in Figure 2.…”

“…The multiple Gaussian functions fit shall be of the following formula, with two to six Gaussian functions fitted separately to each raster image element, the number of fits taken from related studies (Qin et al, 2023),…”

“…Compared with other related methods (Qin et al, 2023;DalsøRen et al, 2016), some of their sources of methane concentration data are atmospheric model data, which may have a bias between them and the actual atmospheric methane concentration, and some of them use satellite observation data as their sources of methane concentration data, but the resolution of their acquired data products is lower than 0.1°in the Chinese region, and the time resolution is monthly. Our research method balances the advantages of the above methods.…”

“…However, due to the highly inadequate resolution of the atmospheric chemistry model data, the outcome achieved is also a general statistical result. Based on this method, researchers compared the simulated groundlevel methane concentration data using a Gaussian function based on an atmospheric chemistry model with total methane column concentrations (Qin et al, 2023). After determining the proportion of ground-level methane concentration in the total methane column concentration, researchers can use this to convert the methane column concentration data collected by the satellite to groundlevel methane concentrations.…”