The Use of Radial Velocity Derivatives to Diagnose Rotation and Divergence

Azimuthal and radial shear fields are extracted from single-Doppler radial velocity data using a two-dimensional, local, linear least-squares technique. The presentation shows how these fields are derived as well as how the technique may be applied to detect and assess the properties of storm-scale rotation and boundaries.

We illustrate that this method of calculating the shear properties of a radial velocity field has several practical uses. Since radial velocity fields cannot be easily visualized in three-dimensional space, the scalar azimuthal and radial shear derivatives provide a useful tool for viewing velocity-derived fields that are not radar-relative. These derived quantities may also be easily integrated into a multi-radar mosaic field or used by multi-radar, multi-sensor algorithms. Image processing techniques are employed to isolate features of significance and remove spurious or noisy data.