Using continental observations in global atmospheric inversions of CO2: North American carbon sources and sinks
M. P. Butler, K. J. Davis, A. S. Denning, and S. R. Kawa
Tellus B: Chemical and Physical Meteorology (1 November 2010)
DOI: 10.1111/j.1600-0889.2010.00501.x
We evaluate North American carbon fluxes using a monthly global Bayesian synthesis inversion that includes well-calibrated carbon dioxide concentrations measured at continental flux towers. We employ the NASA Parametrized Chemistry Tracer Model (PCTM) for atmospheric transport and a TransCom-style inversion with subcontinental resolution. We subsample carbon dioxide time series at four North American flux tower sites for mid-day hours to ensure sampling of a deep, well-mixed atmospheric boundary layer. The addition of these flux tower sites to a global network reduces North America mean annual flux uncertainty for 2001–2003 by 20