Development of a Next Generation Atmospheric General Circulation Model
Masaki Satoh
Frontier Research System for Global Change (FRSGC)
H. Tomita, M. Tsugawa, F. Xiao and T. Nasuno.
Tokyo, Japan
We are developing a next generation high-resolution atmospheric general circulation model which is aimed to be run on the Earth Simulator for the purpose of the prediction of the climate change. The model resolution will be 5-10 km on the sphere and 100 m in the vertical. The fully compressible non-hydrostatic equations are employed as the dynamical framework, and the grid model is chosen for an efficient computation on massive parallel computers. The model development is not yet completed but we are examining from several perspectives: First, two kinds of grid structures are tested with a shallow water model on the sphere: the icosahedral geodesic grids and the conformal cubic grids. Second, a new type of the non-hydrostatic model is developed which conserves mass and energy with horizontally explicit and vertically implicit calculation. Third, a step type mountain coordinate is incorporated to simulate mountain waves with a semi-implicit and semi-Lagrangian CIP scheme. Finally, an impact of the horizontal resolution on the meso-scale convection system is investigated by varying the grid size from 2 km to 5 km.
Within this year 2001, we plan to unify each of the parts of the currently tested models and develop a dynamical core of the non-hydrostatic global model to examine its numerical performances on the Earth Simulator. After that, we will focus on the physical processes such as radiation-convection feedbacks on the new model for the simulation of the global change.
