Dispersion characteristics of discrete quasigeostrophic modes

Abstract

Dispersion characteristics of the shallow water quasigeostrophic modes are discussed for the rectangular grids. It is shown that the propagation of the quasigeostrophic modes is affected by the orientation of the semistaggered grids. Also, it is found that the A and E Arakawa grids produce frequencies of the Rossby waves with the wrong sign, that is, positive instead of negative. The B grid gives better propagation of the quasigeostrophic modes than any of the Arakawa grids. Finally, it appears that the B grid has certain advantages over the Z grid.