Conservative Scheme for a Compressible Nonhydrostatic Model with Moist Processes

Abstract

Abstract A conservative scheme for a compressible nonhydrostatic model including moist processes is formulated and is tested for experiments involving a squall line. The scheme is based on the flux form equations of total density, momentum, total energy, and the densities of water substance. The time-splitting scheme is used for the temporal scheme. In the small time step integration, the horizontal components of momentum are explicitly integrated, while the vertical components of momentum, density, and total energy are implicitly integrated. In particular, the flux form equation for the total energy is used to guarantee the conservation of the total energy. The internal energy is obtained by subtracting the kinetic energy and the potential energy from the total energy. This method is advantageous for the energy budget analysis. Only the warm rain cloud process is included for cloud physics. Using the squall-line experiments, the water budget and the energy budget are diagnosed and it is confirmed that th...