Seasonal variations of greenhouse gas column-averaged dry air mole fractions retrieved from SWIR spectra of GOSAT TANSO-FTS

GOSAT has monitored column-averaged dry air mole fractions of CO₂ and CH4 (XCO₂ and XCH₄, respectively) for cloud-free scenes more than 2 years. The present paper shows the occurrence of the cloud-free data and the seasonal and inter-annual variation of XCO₂ and XCH₄ The seasonal variation of XCO₂ in the boreal hemisphere consists with the previous knowledge from ground-based observation and atmospheric transport model but the relatively small seasonal amplitude of column amount. The globally averaged XCO₂ suggests that the CO₂ concentrations in the atmosphere have increased since 2009 with approximately 2 ppmv. The high temporal variations of XCH₄ are found over the northern subtropics, especially the eastern Asia, however, where the cloud covers frequently during the rainy season. To more precise analysis, it is necessary to accumulate the effective data for analysis or to validate the effect of cloud on retrieved data.