Abstract

A new atmospheric general circulation model (dynamical core) based on the discontinuous Galerkin (DG) method is developed. This model is conservative, high-order accurate and has been integrated into the NCAR's high-order method modeling environment (HOMME) to leverage scalable parallel computing... Show moreA new atmospheric general circulation model (dynamical core) based on the discontinuous Galerkin (DG) method is developed. This model is conservative, high-order accurate and has been integrated into the NCAR's high-order method modeling environment (HOMME) to leverage scalable parallel computing capability to thousands of processors. The computational domain for this 3-D hydrostatic model is a cubed-sphere with curvilinear coordinates; the governing equations are cast in flux-form. The horizontal DG discretization employs a high-order nodal basis set of orthogonal Lagrange-Legendre polynomials and fluxes of inter-element boundaries are approximated with Lax-Friedrichs numerical flux. The vertical discretization follows the 1-D vertical Lagrangian coordinates approach combined with the cell-integrated semi-Lagrangian conservative remapping procedure. Time integration follows the third-order strong stability preserving explicit Runge-Kutta scheme. The domain decomposition is applied through space-filling curve approach. To validate the 3-D DG model in HOMME framework, a baroclinic instability test is used and the results are compared with those from the established models. Parallel performance is evaluated on IBM Blue Gene/L supercomputers. Show less