Dr Susanne Horn, Coventry

Affiliation: Coventry University

Academic Webpage

Title: Generating tornado-like vortices in Coriolis-centrifugal convection

Abstract: Tornadoes are the most intense atmospheric vortices and have been observed on all continents of Earth (except Antarctica), and even on Mars. The most dangerous tornadoes
develop within the mesocyclone of supercell thunderstorms. But what makes a mesocyclone tornadic or not remains one of the greatest mysteries of tornado research, with less than 25%
of mesocyclones producing tornadoes. Magnetic tornadoes have also been observed in the solar atmosphere and are believed to be crucial for coronal heating. Yet, also in the Sun, the
formation mechanisms are far from being fully understood. Thus, the generation of tornadoes and tornado-like vortices is a major and sometimes controversial subject in planetary,
atmospheric, and solar science. Here, I will explore how tornadoes are self-consistently generated in Coriolis-centrifugal convection, that is rotating Rayleigh-Benard convection with ´
the explicit inclusion of centrifugal buoyancy. Turbulent Coriolis-centrifugal convection in a cylindrical domain constitutes an idealised model system of tornadic storms, where the
rotating cylinder represents the mesocyclone of a supercell thunderstorm. I will discuss possible explanations for why seemingly similar mesocyclones may or may not spawn
tornadoes, and how varying boundary conditions and magnetic fields affect the morphology and other flow characteristics. I will show that centrifugal buoyancy is indeed highly relevant
for the understanding of these planetary and solar atmospheric vortices, and likely a key component in next-generation models of tornado physics.