LAUSR

Abstract. As a greenhouse gas with strong global warming potential, atmospheric methane (CH4) emissions have attracted a great deal of attention. Remote sensing measurements can provide information about CH4 sources and emissions. However, accurate assessment of CH4 emissions is challenging due to the influence of aerosol scattering in the atmosphere. In this study, imaging spectroscopic measurements from the Airborne Visible/Infrared Imaging Spectrometer–Next Generation (AVIRIS-NG) in the short-wave infrared are used to analyze the impact of aerosol scattering on CH4 retrievals. Using a numerically efficient two-stream-exact-single-scattering radiative transfer model, we also simulate AVIRIS-NG measurements for different scenarios and quantify the impact of aerosol scattering using two retrieval techniques – the traditional Matched Filter (MF) method and the Optimal Estimation (OE) method, which is a popular approach for trace gas retrievals. The results show that the MF method exhibits up to 50 % lower fractional retrieval bias compared to the OE method at high CH4 concentrations (> 100 % enhancement over typical background values) and is suitable for detecting strong CH4 emissions, while the OE method is an optimal technique for diffuse sources (