Global Concentrations of CO2 and CH4 Retrieved from GOSAT: First Preliminary Results

Abstract

The Greenhouse Gases Observing Satellite (GOSAT) was launched on January 23, 2009, to monitor global atmospheric levels of CO2 and CH4 from space. GOSAT started initial operation of its instruments after an initial satellite system check. Although the radiant data obtained by the GOSAT instruments are currently in the preliminary stages of calibration and validation, the spectral absorption features of CO2 and CH4 are clearly identifiable. An initial retrieval of these gaseous concentrations was performed for measurement scenes of cloud-free conditions over land. These results showed that column-averaged dry air mole fractions of both CO2 and CH4 in the northern hemisphere were higher than those in the southern hemisphere. These latitudinal differences agree with data obtained from groundbased sources and other satellite observations; however, the absolute values of the gaseous concentrations from GOSAT data seem to have been underestimated. Calibrations as well as validation should be conducted to improve the quality of GOSAT retrievals.

Bias corrections of GOSAT SWIR XCO<sub>2</sub> and XCH<sub>4</sub> with TCCON data and their evaluation using aircraft measurement data

“…The Greenhouse gases Observing SATellite (GOSAT), launched in January 2009, is the world's first satellite specialized for measuring the concentrations of atmospheric CO 2 and CH 4 from space (Yokota et al, 2009). Column-averaged dry air mole fractions of CO 2 (XCO 2 ) and CH 4 (XCH 4 ) are retrieved from the Short-Wavelength InfraRed (SWIR) spectra of the Thermal And Near-infrared Sensor for carbon Observation -Fourier Transform Spectrometer (TANSO-FTS) onboard GOSAT.…”

Comparison of GOSAT SWIR and Aircraft Measurements of XCH₄ over West Siberia

“…The Greenhouse gases Observing SATellite (GOSAT) was launched on 23 January, 2009 (Yokota et al 2009;Kuze et al 2009). Since then, the Thermal And Near-infrared Sensor for carbon Observations-Fourier Transform Spectrometer (TANSO-FTS) on board GOSAT has collected global data on carbon dioxide (CO 2 ) and methane (CH 4 ) systematically and continuously.…”

Sources of variations in total column carbon dioxide

“…In contrast, column data provide a constraint on the total mass of CO 2 in a column, and so are more closely related to the underlying fluxes. Observations of column CO 2 from remote sensing platforms such as GOSAT and OCO-2 (Yokota et al, 2009;Crisp et al, 2004) and from ground-based observatories are anticipated to provide better constraints on the exchange of CO 2 between the atmosphere and the surface (Olsen and Randerson, 2004;Chevallier et al, 2007).…”