Skip to main content
Have a personal or library account? Click to login
On the use of reduced grids in conjunction with the Equator-Pole grid system Cover

On the use of reduced grids in conjunction with the Equator-Pole grid system

By:   
Open Access
|Jan 2020

Abstract

This is a continuation of a previous paper by Starius, where for the solution of the shallow water equations on the sphere, we consider Equator-Pole grid systems consisting of one latitude-longitude grid covering an annular band around the equator, and two orthogonal polar grids based on modified stereographic coordinates. Here, we generalise this by letting an equatorial band be covered with a reduced grid system, which can decrease the total number of grid points by at least 20%, with no substantial change in accuracy. Centred finite differences of high order are used for the spatial discretisation of the underlying differential equations and the explicit fourth order Runge-Kutta method for the integration in time. In the paper mentioned above, we demonstrate accuracy in the total mass, which is much higher than needed for NWP, for smooth solutions. Here we show that this holds also for non-smooth solutions, by considering the Cosine bell no. 1 and the mountain problem no. 5 in Williamson et al., the solutions of which have discontinuous second and first order derivatives, respectively.

Language: English
Page range: 1792736 - 1792736
Published on: Jan 1, 2020
Published by: Stockholm University Press
In partnership with: Paradigm Publishing Services

© 2020 Göran Starius, published by Stockholm University Press
This work is licensed under the Creative Commons Attribution 4.0 License.