Vortex Gas Models for Tornadogenesis and Maintenance
DOI:
https://doi.org/10.9734/bpi/ntpsr/v2/2138BKeywords:
Vortex gas, negative temperature, supercritical vortices, inverse energy, cascade, tornadogenesis, tornado maintenance, barotropic vorticity, baroclinic vorticity, statistical mechanics of vortex gas, thermodynamics, entropy, rear flank downdraft, forward flank downdraft, suction vortices, fluid dynamics, boundary layer, breakdown of cyclostrophic balance, Euler equations, turbulenceAbstract
Tornadogenesis is thought to be influenced by processes related to the generation of vorticity in the forward and rear flank downdrafts, as well as their interaction with the boundary layer. Our goal is to show that vortex gas models are an appropriate tool to describe the processes of tornadogenesis and maintenance. We suggest that an inverse energy cascade is a feasible process for tornadogenesis and tornado maintenance, and we give computational and observational data to back up our claim. We use a three-dimensional vortex gas model to simulate supercritical vortices at the surface boundary layer, which could be caused by interactions between vortices delivered to the surface by the rear flank downdraft and those connected to the forward flank downdraft. In the statistical mechanics context, negative temperatures are higher than positive temperatures. Two-dimensional and three-dimensional vortex gas models are discussed, the three-dimensional vortex gas model of Chorin, developed further by Flandoli and Gubinelli, is proposed as a model for intense small-scale subvortices found in tornadoes and in numerical and radar studies.
