A laboratory study of Hurricane mesovortices

Radar observations of intense hurricanes indicate the existence of intense "mesovortices" within and near the hurricane eyewall region. Recent theoretical work has implicated the importance of such structures in the realization of intense storms and rapid intensification.

We suggest that the mechanism of their generation and maintenance is similar to that of the formation of a system of vortices above an orifice in the bottom of a vessel with a steady supply of circulating liquid along the vessel's periphery.

An experimental set up for producing "hurricane-like" core flows has been manufactured and used. Measurements of fluid velocity are obtained using a Particle Image Velocimetry (PIV) system. Near the model "eyewall"radius the velocity pulsations are measured to get as high as 1.4 times the azimuthal mean tangential wind. These measurements are believed useful estimates of the wind variability in intense hurricanes over open ocean.

The characteristics of the mesovortices and the stability properties of the basic state flow which supports them will be presented.