A SEMI-IMPLICIT SCHEME FOR GRID POINT ATMOSPHERIC MODELS OF THE PRIMITIVE EQUATIONS

Abstract A semi-implicit time integration scheme tested earlier with a spectral model is now adapted to a grid point model of the primitive equations. Predictions prepared by the implicit method compare quite favorably with the forecasts produced by an explicit technique. The implicit model runs about four times faster; and after 5 days of integration, the forecasts differ by less than 20 m.