Computation and Uses of Gradient Winds

The viewpoint is taken that in large port>ions of the atmospherc, wind spcclds (V,,), divergence (D,?), and vor-ticity (r,?) obtained under the gradient wind assnmptiorl are considerably morc accurate representations of true conditions than those one obtains from the geostrophic assumption. Equations are derived for computing V,,, D,,, and rgl. The equation for the vorticity of gradicnt' winds has a considtlrahle resemblance to " balance " equations of Charney [3] and Phillips [17]. Gradient \vinds and t,heir space derivatives may have advantages over other formulations due to their relative simplicity. The quantities V g r , D,,, and cgr may be compnted yuitc easily from geopotential data at grid points by use of high-speed computers. Possible applications of gradient winds in practical and theoretical meteorology arc suggested.