Theoretical outline of a family of one-level models for numerical forecasting in the Southern Hemisphere

The implications of the equivalent barotropic model are briefly reviewed and it is shown how fields of vertical velocity and diabatic heating inherent in the model may be derived analytically. The techniques employed are then extended to produce a consistent group of one-level numerical forecast models especially suited to sparse data areas such as the Southern Hemisphere. The general form of the prognostic equation for all these models is shown to be the same. Provision is made in the more sophisticated models for the input of diabatic heating and vertical velocity fields at an upper and lower boundary as part of the initial data. All models enable these fields to be computed from the contour pattern at the forecast level or at any arbitrary isobaric surface within the vertical extent of the atmosphere under consideration.