SEMI-LAGRANGIAN HIGH-RESOLUTION MODEL OF THE ATMOSPHERE FOR NUMERICAL WEATHER PREDICTION

M. A. Tolstykh

A global semi-Lagrangian finite-difference atmospheric general circulation model is presented which provides for the configuration with a rotated pole of the spherical coordinate system and a variable resolution in latitude. The distinct features of this model are the application of the fourth-order compact finite differences for the approximation of nonadvective terms combined with the use of the vertical component of absolute vorticity and the horizontal divergence as prognostic variables. The results of model validation by a series of five-day forecasts using the configuration with constant resolution in latitude show the advantages of the proposed approach.