Development of an Integrated Earth System Model on the Earth Simulator

Frontier Research Center for Global Change (FRCGC) launched in FY 2002 a project to develop an integrated earth system model that operates on the Earth Simulator, in collaboration with the Center for Climate System Research of the University of Tokyo, National Institute of Environmental Studies. The project aims at development of a model where biological and chemical processes important for the global environment are included to interact with climate changes. The model is developed by adding individual component models to atmospheric and oceanic general circulation models (GCMs). The component models are terrestrial and oceanic carbon cycle models and an atmospheric chemistry model. Improvements of the physical climate model are required in order to extend the model top to the middle atmosphere. Preliminary results with fully-coupled climate - carbon cycle model show a significant positive feedback between climate change and carbon cycle, while another preceding model exhibits an even stronger feedback. Other foci of the project include: experiments with the atmospheric chemistry component model, which demonstrate that impact of climate change on other green house gases such as tropospheric ozone and methane could be significant; examination of resolution-dependence of momentum transfer to the stratosphere by gravity waves using high resolution Atmospheric GCMs which explicitly resolve gravity waves.