全球に適用可能な非静力学大気力学コアの定式化

Abstract

A simple and stable non-hydrostatic formulation is proposed and tested using the National Centers for Environmental Prediction Mesoscale Spectral Model (NCEP MSM) in idealized experiments. MSM uses double-Fourier series for horizontal discretization and a vertical coordinate based on the hydrostatic pressure. MSM requires the hydrostatic temperature specified externally or evolved internally. The new formulation uses the horizontally averaged temperature as the hydrostatic temperature to enable its applications to the global domain without an additional prognostic variable. The modified MSM runs stably in the warm and cold bubble experiments. The noise in the perturbation pressure indicative of sound waves may be controlled by the size of the horizontal average of the temperature.