Identification and elimination of an inflow boundary computational solution in limited area model integrations

Abstract

Abstract The linearized non‐divergent barotropic vorticity equation in one dimension is used for the study of a problem associated with the specification of lateral boundaries in limited area models. This problem presents itself in the form of a “pillow” that builds up near the inflow boundary of the model. Linear analysis shows that this pillow can easily be eliminated. Linear integrations carried out with a corrector seem to be reasonably accurate. Similar integrations with the linearized shallow water equations in one dimension also produce a pillow and the same corrector gives improved results. Additional runs are performed in order to show that some commonly used nesting strategies do not control this computational problem in a satisfactory manner. It seems that these strategies could be improved with an appropriate corrector.