Column-averaged dry air mole fractions of carbon dioxide (XCO2) measured by the Greenhouse Gases Observing Satellite (GOSAT) reveal significant interannual variation (IAV) of CO(2)uptake during the Northern Hemisphere summer between 2009 and 2010. The XCO(2)drawdown in 2010 is shallower than in 2009 by 2.4ppm and 3.0ppm over North America and Eurasia, respectively. Reduced carbon uptake in the summer of 2010 is most likely due to the heat wave in Eurasia driving biospheric fluxes and fire emissions. A joint inversion of GOSAT and surface data estimates an integrated biospheric and fire emission anomaly in April-September of 0.89 0.20 PgC over Eurasia. In contrast, inversions of surface measurements alone fail to replicate the observed XCO(2)IAV and underestimate emission IAV over Eurasia. This shows the value of GOSAT XCO(2)in constraining the response of land-atmosphere exchange of CO2 to climate events.
- column observing network