Crevoisier, C., M. Gloor, E. Gloaguen, L. W. Horowitz, J. L. Sarmiento, C. Sweeney and P. P. Tans, (2006), A direct carbon budgeting approach to infer carbon sources and sinks. Design and synthetic application to complement the NACP observation network, Tellus Series B: Chemical and Physical Meteorology, 58, 5, 366-375, 10.1111/j.1600-0889.2006.00214.x


In order to exploit the upcoming regular measurements of vertical carbon dioxide (CO2) profiles over North America implemented in the framework of the North American Carbon Program (NACP), we design a direct carbon budgeting approach to infer carbon sources and sinks over the continent using model simulations. Direct budgeting puts a control volume on top of North America, balances air mass in- and outflows into the volume and solves for the surface fluxes. The flows are derived from the observations through a geostatistical interpolation technique called Kriging combined with transport fields from weather analysis. The use of CO2 vertical profiles simulated by the atmospheric transport model MOZART-2 at the planned 19 stations of the NACP network has given an estimation of the error of 0.39 GtC yr(-1) within the model world. Reducing this error may be achieved through a better estimation of mass fluxes associated with convective processes affecting North America. Complementary stations in the north-west and the north-east are also needed to resolve the variability of CO2 in these regions. For instance, the addition of a single station near 52 degrees N; 110 degrees W is shown to decrease the estimation error to 0.34 GtC yr(-1).