MODELING AND NUMERICAL APPROXIMATION OF A 2.5D SET OF EQUATIONS FOR THE ATMOSPHERE

Abstract. In this talk we present a new layered model for atmospheric applications. The model is derived from the compressible Euler equations including an energy equation with po-tential temperature (entropy) as the temperature variable. After vertical integration this leads to a set of 2D equations for each layer with stiff source terms, coupled via the vertical velocity between the layers. Such formulation is nonconservative, and the application of standard finite volume techniques is not possible. The main numerical issues that arise in this context are the efficient implementation of non-reflecting boundary conditions for the lateral boundaries, the splitting to incorporate the source terms properly and the numerical solution of the advective part of the model. The model will be used in data assimilation experiments using ensemble Kalman filter techniques