The operational solution of the balance equation

Abstract

The balance equation is commonly used to provide accurate non-divergent initial wind fields for prognostic models. The most important technical operational problems occurring in the numerical solution of the equation are examined. Methods of convergence are proposed, which are accurate and economical of computer time. The specific points treated are the convergence criterion, the relaxation factor, a correction technique for the residual error and a simple method of selective relaxation. Typical error fields at 500 mb illustrate the accuracy of the proposed method.