A direct carbon budgeting approach to infer carbon sources and sinks. Design and synthetic application to complement the NACP observation network
Horowitz, Larry W.
Sarmiento, Jorge L.
Tans, Pieter P.
- Publisher: Tellus B
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°N; 110°W is shown to decrease the estimation error to 0.34 GtC yr−1.DOI: 10.1111/j.1600-0889.2006.00214.x