A Positive Definite Advection Scheme for Use in Long Range Transport Models: Extension to Monotonicity

摘要: Numerical modeling of atmospheric transport processes requires the solution continuity equation for prognostic variables such as momentum, heat, water vapor, liquid or chemical species atmosphere. Although in literature many advection schemes are known to solve this problem (Lax and Wendroff 1964, Crowley 1968, Tremback et al. 1987, Bott 1989a,b), these algorithms show different disadvantages, which sometimes yield undesirably poor numerical results. For instance, upstream method is produce large diffusion. The higher order versions (1987) much less diffusive. Unfortunately, not positive definite, thus yielding some cases negative values definite quantities concentrations species.