This study investigates the response of the global mean and spatial variations of the δ¹⁸O value of atmospheric CO₂ (δCₐ) to changes in soil CO₂ hydration rates, relative humidity, the δ¹⁸O value of precipitation and water vapor, visible radiation, temperature, and ecosystem flux partitioning. A three-dimensional global transport model was...
Accurately simulating gross primary productivity (GPP) in terrestrial ecosystem models is critical because errors in simulated GPP propagate through the model to introduce additional errors in simulated biomass and other fluxes. We evaluated simulated, daily average GPP from 26 models against estimated GPP at 39 eddy covariance flux tower sites...