= Counterpropagating wave resonance in a three-layer shear flow
{title2=$1+J=2\alpha$}
For stable density jumps in the <three-layer stratified piecewise-linear shear flow>, the upper interface's intrinsically left-going <gravity-vorticity interface wave> and the lower interface's intrinsically right-going wave have opposite laboratory <phase velocities>. They coincide at zero when $1+J=2\alpha$. At large <wavenumber>, interaction is of order $e^{-2\alpha}$ and the <unstable band of a three-layer stratified shear flow> has width $4\alpha e^{-2\alpha}+O(\alpha e^{-6\alpha})$ around this resonance.
Back to article page
