Microtornadoes under a Nanocrystalline Igloo: Results Predicting a Worldwide Intensification of Tornadoes

When a sessile water drop of radius R containing polystyrene nanospheres evaporates in an open Petri dish, the nanospheres eventually form a dense layer of nanoclay enclosed by a ring of radius r ≤ R. When it evaporates in a closed Petri dish, the predominant structure is a crystalline ring with a thin nanoclay film in its interior. When it evaporates in a closed and well-sealed Petri dish, securing a constantly high vapor pressure, instead of a ring, a crystalline igloo with multiple cells emerges. Light microscopy complemented by scanning electron microscopy provides evidence for vortices in the igloo (one per cell), which could only be formed by microtornadoes. Tornadoes with intense vortices are distinctive for thunderstorm cells (supercells) in association with deep moist convection driven by pre-existing warmer humid air at the ground, overrun by a cold front. A precondition for realistic tornadogenesis studies based on experimental models is the coexistence of a humid air layer at the ground with a...