Multispectral information from TANSO-FTS instrument – Part 2: Application to aerosol effect on greenhouse gas retrievals

摘要

This article is the second in a series of studies investigating the benefitsof multispectral measurements to improve the atmospheric parameterretrievals. In the first paper, we presented an information content(IC) analysis from the thermal infrared (TIR) and shortwave infrared (SWIR)bands of Thermal And Near infrared Sensor for carbon Observations–Fourier Transform Spectrometer (TANSO-FTS) instrument dedicated to greenhouse gas retrieval inclear sky conditions. This second paper presents the potential of thespectral synergy from TIR to visible for aerosol characterization, andtheir impact on the retrieved CO₂ and CH₄ column concentrations.The IC is then used to determine the most informative spectral channels forthe simultaneous retrieval of greenhouse gas total columns and aerosolparameters. The results show that a channel selection spanning the fourbands can improve the computation time and retrieval accuracy. Therefore,the spectral synergy allows obtaining up to almost seven different aerosolparameters, which is comparable to the most informative dedicatedinstruments. Moreover, a channel selection from the TIR to visible bandsallows retrieving CO₂ and CH₄ total columns simultaneously inthe presence of one aerosol layer with a similar accuracy to using allchannels together to retrieve each gas separately in clear sky conditions.