INSTABILITY OF COROTATING VERTICAL VORTICES IN A STRATIFIED FLUID: WHY STRONGLY STRATIFIED TURBULENCE IS NOT SIMILAR TO 2D TURBULENCE

摘要

We present numerical, theoretical and experimental studies of a new instability of two corotating vertical vortices in a vertically stratified fluid. This instability induces the formation of thin horizontal layers with a thickness inversely proportional to the Brunt-Vaisala frequency. This three-dimensional instability is believed to make stratified turbulence depart from two-dimensional turbulence since it alters the pairing of vortices.