Yy. Lu et al., ESTIMATING LARGE-SCALE VORTICITY USING VAD PRODUCTS AND REFLECTIVITY, Journal of atmospheric and oceanic technology, 13(6), 1996, pp. 1129-1138
Velocity-azimuth display (VAD) products (i.e., wind, divergence, defor
mations, etc.) and a Lagrangian advective scheme applied to the reflec
tivity factor field are jointly used to estimate vertical profiles of
vorticity. The reflectivity field is assumed to be conserved over the
time period between radar observations. The vorticity selected gives t
he best least squares fit between observed and predicted reflectivity
fields. These results suggest that vorticity is retrieved with a preci
sion better than about 1 x 10(-5) s(-1) for scales on the order of 100
km and larger. The vorticity profiles are consistent with U.S. Nation
al Weather Service's analysis. The surface value of vorticity, extrapo
lated from the estimated profiles, is also compared with the vorticity
calculated from Oklahoma mesonet data. The agreement is within the es
timated standard error.