ABSTRACT
Vortices are observed in nature in many di§erent situations and invarioustypesofappearance.Forexample,intheatmosphere organizedvortexmotionisobservedinlarge-scaledepressions, cyclones,tornadoes,andonsmallerscalesindustdevilsand waterspouts.Less-organizedvortexstructuresarealsoabundant,forexample,intheformofturbulenteddiesindeveloping cumulusclouds,intheturbulentžowofsmokeemanatingfrom activevolcanoesorindustrialchimneys,andalsointhevertical motion around large buildings on a windy day.
