Coordinates over Complex Terrain in Atmospheric Model

Abstract

In the terrain following coordinate, Gal-Chen and Somerville and other proposed a vertical coordinate and constant spatial intervals of and along the other directions. Because the variation of and was ignored, their coordinate does not really follow the terrain. It fails to reproduce the divergence and curl over a complex terrain. Aligning the coordinate with real terrain, the divergence and curl we obtained from the curvilinear coordinate are consistent with the Cartesian coordinate. With a modification, the simulated total mass, energy, and momentum from the Navier-Stokes equations are conserved and in agreement with those calculated from Cartesian coordinate.