A new parametric model of vortex tangential wind-profile: Testing and verification

Wood and White (2010) formulated a new parametric vortex wind-profile model with applications to Doppler radar observations of dust devils, tornadoes, supercell mesocyclones, and Quasi-Linear Convective Systems (QLCS) mesovortices. The model employs the five key parameters: maximum tangential wind (Vx), radius (Rx) at which Vx occurs, curvature growth (k) that controls the inner tangential velocity near the vortex center, decay (n) that decreases the outer tangential velocity beyond Rx with increasing radial distances from vortex center, and radial width (lambda) that controls a discontinuous or continuous tangential velocity maximum at Rx. Radial profile families of tangential wind in the Wood-White (2010) parametric model compared favorably to those of Doppler radar observations of vortices, and theoretical vortex models including the Rankine vortex.

Test results show that the use of the parametric model may garner new insights to two-dimensional vortex structure by critically examining the radial and vertical profiles of the model parameters that have been obtained by fitting the parametric model to the radial profiles of numerical tangential velocity output. The excellent agreement between the fitted and numerical tangential wind speeds indicates that the parametric model can accurately capture the tangential velocity distribution in the vortex structure and demonstrates the capability of the parametric model in practical applications such as model initialization, data fitting and retrieval techniques. An example of fitting the parametric model to the mobile Doppler radar-derived tangential velocity profile of the Texas dust devil of 25 May 1999 is also discussed.

Reference: Wood, V. T., and L. W. White, 2010: A new parametric tangential wind model for intense atmospheric vortices. Prepared for JAS. -->