Land-atmosphere CO₂ exchange simulated by a land surface process model coupled to an atmospheric general circulation model

CO₂ uptake during plant photosynthesis and CO₂ loss during plant and microbial respiration were added to a land surface process model to simulate the diurnal and annual cycles of biosphere-atmosphere CO₂ exchange. The model was coupled to a modified version of the National Center for Atmospheric Research Community Climate Model version 2, and the coupled model was run for five years. The geographic patterns of annual net primary production are qualitatively similar to other models. When compared by vegetation type, annual production and annual microbial respiration are consistent with other models, except for needleleaf evergreen tree vegetation, where production is too high, and semidesert vegetation, where production and microbial respiration are too low. -from Author