On the Approximation of the Coriolis Terms in C-Grid Models

Abstract

A new representation of the Coriolis terms on the Arakawa C grid is proposed. The approximation dumps the grid-scale noise that arises because of spatial averaging of the Coriolis terms when the grid spacing is larger than the deformation radius. The proposed approximation can also be applied in C-grid schemes with semi-implicit treatment of the Coriolis terms. The new scheme is analyzed in the context of the linear inertial?gravity waves and its advantageous behavior is demonstrated with respect to the conventional technique.