Intercomparison of Spatial Interpolation Schemes for Use in Nested Grid Models

Abstract

Two geometrical and two advection-equivalent spatial interpolation schemes were tested in providing lateral boundary conditions to a nested grid domain. Geometric interpolation schemes used in this study are a zeroth- order and a quadratic scheme, while the two advection-equivalent interpolation schemes were based on upwind and Bott?s advection schemes. The test problem involves an initially cone-shaped distribution of a scalar advected from a coarse to a fine grid. Simulation results were compared to the exact solution to study magnitude and phase characteristics of each scheme. Results indicated that Bott?s advection-equivalent interpolation scheme provided better interface conditions and, consequently, a more accurate transition of the signal from a coarse to a fine grid.