Significance of the Coupled Term in the Doppler Weather Radar Spectrum Width Equation

Abstract

here is an additional zero mean random variable term that couples mean wind shear and turbulence in the Doppler radar spectrum width equation. This random variable, labeled the ?coupled term,? has been neglected heretofore in the literature. Herein, the variance of the squared spectrum width ascribed to this coupled term is determined from data collected with a Weather Surveillance Radar-1988 Doppler (WSR-88D) in two snowstorms; it can exceed 1 m4 s?4. Thus, this coupled term can be a significant contributor to the variance of the spectrum width and must be considered when using spectrum width to deduce turbulence.