Design of a new dynamical core for global atmospheric models based on some efficient numerical methods

Abstract

A careful study on the integral properties of the primitive hydrostatic balance equations for baroclinic atmosphere is carried out, and a new scheme to design the global adiabatic model of atmospheric dynamics is presented. This scheme includes a method of weighted equal-area mesh and a fully discrete finite difference method with quadratic and linear conservations for solving the primitive equation system. Using this scheme, we established a new dynamical core with adjustable high resolution acceptable to the available computer capability, which can be very stable without any filtering and smoothing. Especially, some important integral properties are kept unchanged, such as the anti-symmetries of the horizontal advection operators and the vertical convection operator, the mass conservation, the effective energy conservation under the standard stratification approximation, and so on. Some numerical tests on the new dynamical core, respectively regarding its global conservations and its integrated performances in climatic modeling, incorporated with the physical packages from the Community Atmospheric Model Version 2 (CAM2) of National Center for Atmospheric Research (NCAR), are included.