. Two-dimensional Hadley Circulation modeling toward high resolution climate simulation

Abstract
Numerical simulation of the global climate is a powerful tool for climate science, but it requires large computational resources. The Energy Exascale Earth System Model (E3SM) is a new generation climate model developed by DOE, and a future version will be run on a high resolution (3 km horizontal mesh) with cutting-edge schemes representing atmospheric turbulence and cloud microphysics. However, physical performance and lurking difficulties in these new physical schemes in a high-resolution climate model with massively parallel machines are unknown. In this presentation, we approach these problems by applying two-dimensional Hadley circulation simulations which can avoid huge computation. The Hadley circulation is a nice representative of the climate, and it can be simulated essentially in a meridional-vertical plane. The framework was developed by modifying the System for Atmospheric Modeling (SAM). Since two-dimensional simulation is simple and lightweight, we can save computation in the zonal direction and easily increase model resolution and experiment cases. A test experiment has been started using 2 km horizontal grid spacing. 50 days of time integration with 512 cores of CPU was carried out only for 4 days. The results show realistic features of the Hadley circulation and suggest a really useful framework for testing, inter alia, model parameterizations and their influence on the circulation.