Abstract: Three total column dry-air mole fractions of CO₂ (XCO₂) products from satellite retrievals, including SCIAMACHY, NIES-GOSAT, and ACOS-GOSAT, in the Northern Hemisphere were validated by ground data from the Total Carbon Column Observing Network (TCCON). The results show that the satellite data show the same seasonal fluctuations with TCCON, in general with maximum in April or May and minimum in August or September. The three products all underestimate the XCO₂. The accuracy of the ACOS-GOSAT product is almost the same as the NIES-GOSAT product, and their mean standard deviations are 2.26×10^-6 and 2.27×10^-6 , respectively. The accuracy of the SCIAMACHY product is slightly lower, with mean standard deviation of 2.91×10^-6.

Key words: CO₂, satellite remote sensing, validation