CO₂ source inversions using satellite observations of the upper troposphere

Satellite observations of CO 2 abundance in the upper troposphere can provide a major constraint for deriving the net carbon fluxes from tropical landmasses that is unavailable from current surface observations. Such global CO 2 profiling with an uncertainty of about 1% (3 ppm) contains key longitudinal information needed to derive surface fluxes in a standard Bayesian inversion. Upper‐tropospheric data available from flight‐proven FTIR solar occultation measurements could provide comparable information to that from yet‐to‐be‐demonstrated column CO 2 observations, which have heretofore been the focus of carbon cycle studies. A strategy for improving CO 2 source inversions with either type of satellite data should focus on tropical observations and on careful evaluation of possible sampling biases affecting the observational uncertainties.