On the accuracy of the CO£2 surface fluxes to be estimated from the GOSAT observations

This paper quantifies the value added by the Greenhouse gases Observing SATellite (GOSAT) to numerical models of the global carbon cycle for the estimation of CO 2 surface fluxes. The metric used here is the theoretical uncertainty reduction, defined as one minus the ratio of the posterior flux uncertainty to the prior ones. Our results indicate that GOSAT should significantly improve our knowledge of the CO 2 surface fluxes over terrestrial vegetated areas, even at the scale of a week and of a few hundred kilometres. Over ocean and in spite of the GOSAT sun‐glint‐pointing capability, large improvements are seen only when the fluxes are aggregated both over ocean basins and over a year.