A preliminary study on GOSAT L1B data and CO2 absorption spectral simulation using line-by-line radiative model

Greenhouse gases Observing SATellite(GOSAT) provide CO₂ absorption spectral and CO₂ concentration data from space for the first time. Mt.Waliguan is one of the stations in global atmosphere watch network, which is far away from anthropogenic CO₂ emissions, and provide in situ CO₂ concentration of Eurasian continent. GOSAT FTS L1B CO₂ absorption spectral and the corresponding L2 CO₂ concentration data at Mt.Waliguan area(1°×1°window)are analyzed. The impact of aerosol and surface albedo on CO₂ absorption bands are also evaluated using Line-by-line radiative model(LBLRTM) considering GOSAT FTS spectral characteristics..The initial study shows first GOSAT FTS band2 detected CO₂ spectrums are consistent with the observation conditions. Second, as aerosol reduced the atmospheric transmittance, the simulated radiance decreased, but urban aerosol have more influence to the simulated CO₂ spectral than rural aerosol, Third, if not considering the observation angle, when the ground have low surface albedo, the radiant energy of satellite can detected are very weak, which means satellite have to enhance SNR to detect little CO₂ concentration change.