Quantification of the atmospheric aerosol effect on global terrestrial ecosystem carbon budget during the period of 2001-2008

Previous studies have illustrated the aerosol light scattering effect on terrestrial carbon cycling either by means of site-level observations or land surface model simulations. Here we develop a model framework by integrating a daily process-based biogeochemical model, the Terrestrial Ecosystem Model (TEM), an atmospheric radiative transfer module and a canopy radiative transfer module to fully account for the effect on terrestrial photosynthesis, respiration and evapotranspiration. The aerosol light scattering effect is quantitatively simulated by the atmospheric radiative transfer algorithms using the MODIS daily atmosphere products (MOD08_D3 and MYD08_D3). We apply the model framework to the globe for the MODIS era (2001-2008). Our results indicate that the existence of aerosol increases the terrestrial photosynthesis while reducing the respirations and therefore enhances the global terrestrial carbon sink at a significant level during our study period. The southeast and east Asia, the east United States, the Europe as well as the Middle Africa are influenced the most by the aerosol effects. This study highlights the importance of considering the aerosol effects in quantifying the global carbon budget.