Applications of vortex gas models to tornadogenesis and maintenance

TL;DR

This paper explores how vortex gas models, especially the inverse energy cascade mechanism, can explain tornadogenesis and tornado maintenance through numerical and observational evidence.

Contribution

It applies a 3D vortex gas model to supercritical vortices, proposing a novel explanation for tornado formation and persistence based on inverse energy cascade dynamics.

Findings

Inverse energy cascade plausibly explains tornadogenesis.

3D vortex gas model captures small-scale subvortices in tornadoes.

Surface boundary interactions generate supercritical vortices.

Abstract

Processes related to the production of vorticity in the forward and rear flank downdrafts and their interaction with the boundary layer are thought to play a role in tornadogenesis. We argue that an inverse energy cascade is a plausible mechanism for tornadogenesis and tornado maintenance and provide supporting evidence which is both numerical and observational. We apply a three-dimensional vortex gas model to supercritical vortices produced at the surface boundary layer possibly due to interactions of vortices brought to the surface by the rear flank downdraft and also to those related to the forward flank downdraft. Two-dimensional and three-dimensional vortex gas models are discussed, and 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 recent numerical studies by Orf et al. In this paper, the smaller scales are represented by intense, supercritical vortices, which transfer energy to the larger-scale tornadic flows (inverse energy cascade). We address the formation of these vortices as a result of the interaction of the flow with the surface and a boundary layer.