Nonlinear OIFS for a hybrid Galerkin atmospheric model

Abstract

The purpose of this paper is to explore a time-split hybrid Galerkin scheme for the atmospheric shallow water equations. A nonlinear variant of operator integration factor splitting is employed as the time-stepping scheme. The hyperbolic system representing slow modes is discretized using the discontinuous Galerkin method. An implicit second order backward differentiation formula is applied to Coriolis and gravity wave terms. The implicit system is then discretised using a continuous Galerkin spectral element method. The advantages of such an approach include improved mass and energy conservation properties. A strong-stability preserving Runge-Kutta scheme is applied for sub-stepping. © Springer-Verlag Berlin Heidelberg 2005.