Mid Tropospheric CO2 measurement with AIRS

We present an improved global measurement of CO2 with peak sensitivity around 500 mbar using the AIRS instrument. The demands of the CO2 retrieval led us to produce an improved radiative transfer model that is in better agreement with line-by-line calculations, improving our retrieval by ~2 ppm in dry regions. Globally we observe a higher CO2 inhomogeneity between continents and the oceans than in the NOAA CarbonTracker assimilated model, similar to SCHIAMACHY results. This suggests significant different transport than used by CarbonTracker. A number of localized features are observed, for example, anthropogenic CO2 plumes over the Eastern USA during the Fall, when the natural CO2 cycle is near a minimum.