COMPARISON OF ATMOSPHERIC CARBON DIOXIDE CONCENTRATION BASED ON GOSAT AND OCO-2 OBSERVATIONS

So far, the Greenhouse Gases Observing Satellite (GOSAT) and the Orbiting Carbon Observatory-2 (OCO-2) are the only two missions designed to measure the column-averaged CO2 dry air mole fraction (XCO2). To improve our understanding of global carbon source and sink, these two XCO2 products are compared in this study. The result reveals that the OCO-2 XCO2 product show the wider spatial coverage than those of GOSAT from 30 degrees S similar to 90 degrees N latitude. At the same time, GOSAT and OCO-2 XCO2 products shows a good agreement with correlation coefficient (R-2) of 0.69 and bias of -1.0 ppm. However, the discrepancy is still existed in some region. The discrepancy between these two products implies that it is necessary to make them complement each other to better improve our knowledge of global carbon cycle or even climate change.