Multiple vortices induced by a tridimensional critical layer in a rapidly rotating vortex

作者：Caillol Philippe^*

来源：IMA Journal of Applied Mathematics, 2012, 77(3): 282-292.

DOI：10.1093/imamat/hxs030

• geophysical vortex dynamics
• linear stability of a vortex
• wave-vortex interactions
• critical layer
• neutral vortex Rossby mode

This study aims to predict the intensification or the weakening of a rapidly rotating vortex of a hurricane or tornado type through the examination of its interaction with the waves that propagate therein. In this simplified analytical model, we consider the propagation of neutral, non-linear and singular vortex Rossby modes of a barotropic and axisymmetric vortex in the f-plane. The wave-vortex interaction is then characterized by the appearance of a secondary flow which diffuses in an asymmetric way at either side of a 3D critical layer that winds up around the vortex axis. The mean azimuthal and axial momentum change rates are proportional to the basic vorticity gradient at the critical radius and inversely proportional to the fourth power of the critical-layer thickness. For a stable basic vortex, the mean azimuthal motion decelerates.

• 出版日期2012-6