全球雲解像モデルによるエアロゾル間接効果の研究

抄録

This paper reviews a recent study of aerosol indirect effect using a global cloud-resolving model. The new global cloud-resolving model NICAM recently developed for the Earth Simulator was coupled with SPRINTARS aerosol transport model for simulating the aerosol effects on convective clouds. Numerical experiments were performed using the NICAM-SPRINTARS model with horizontal resolution of 7 km, and the simulated results were compared with satellite observations of clouds and aerosols. The results showed several important aspects of cloud microphysical properties and their interactions with aerosols, which have been difficult to simulate with traditional climate models. This includes detailed spatial structures of cloud droplet effective radius, global correlation statistics of liquid water path with aerosols and vertical growth patterns of cloud droplets interacting with aerosols. These results demonstrate that the interactions of aerosols with convective clouds, for the first time, are represented by global-scale model, providing a new capability for studying the climatic effects of aerosols. We also discuss several issues with the model that should be addressed in future studies.