VAD Analysis of Nonlinear Wind Fields

Abstract

A critical review of the velocity-azimuth display (VAD) analysis for the retrieval of wind, divergence, and deformation from single-Doppler observations is presented. It is shown that in situations when the linear wind assumption is not valid the VAD analysis leads to incorrect conclusions. The range and height dependence of single-Doppler data contains information on the nonlinearity of the wind field and allows a generalized analysis by which vertical profiles of wind, divergence, and deformation at the radar site can in principle be obtained. These ideas are illustrated by two case analyses of single-Doppler observations in clear air.