On the modal structure of shear-induced instabilities in stratified fluids

The instability of stratified fluids in horizontal sheared motion is considered. It is shown that the presence of Brunt-Vaisala frequency jumps along the vertical direction gives rise to unstable modes different from the well-known Kelvin-Helmholtz instability. These modes are studied and some of their most important characteristics are described. The analysis is carried out numerically. The results obtained are compared with those of other authors.