On the Application of Trajectory Methods in Numerical Forecasting

On the basis of a comparison between the results so far obtained by the usual numerical methods in physical weather prediction and the graphical methods it is likely that certain defects in the present forecast methods are due to the Eulerian technique. The possibilities for the use of a quasi-Lagrangian technique are investigated, and it is found that such a technique is possible and becomes especially simple when combined with a space-smoothing which eliminates the shorter fast moving waves in the spectrum. The Lagrangian method of computation is described in the barotropic case and also for a simplified two-parameter baroclinic model.