Reconstruction of wind profiles in dust devils: analyses of W-band mobile radar data using the Ground-Based Velocity Track Display (GBVTD) technique

On the afternoon of 25 May 1999, high-resolution radar data were collected in several dust devils near Childress, Texas, by a mobile, W-band Doppler radar. High-resolution reflectivity and radial velocity were measured in these small-scale vortices at a range of less than 1.5km, the detailed discussion of which has been presented previously. The Ground-Based Velocity Track Display (GBVTD) technique was applied to these high-resolution dust devil data in much the same manner as has been applied to similar data collected in tornadoes. In this study, radial profiles of GBVTD-analyzed radial and azimuthal winds, circulation, divergence, and vertical vorticity will be presented. The azimuthally-averaged azimuthal velocity profiles of the dust devils will be compared to the azimuthal velocity profile of an idealized Burgers-Rott vortex with the same radius of maximum wind and peak azimuthal wind. These results will be compared to previous GBVTD analyses of high-resolution radar data collected in tornadoes. Given the small radius of the dust devils relative to tornadoes previously examined using this technique, the impacts upon the GBVTD analyses of the different scales of spatial resolution and sampling of these vortices will also be examined.