Instability of a two-step Rankine vortex in a reduced gravity QG model

Xavier Perrot (1) , Xavier J. Carton (2)

1 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
2 LPO - Laboratoire de physique des océans

We investigate the stability of a steplike Rankine vortex in a one-active-layer, reduced gravity, quasi-geostrophic model. After calculating the linear stability with a normal mode analysis, the singular modes are determined as a function of the vortex shape to investigate short-time stability. Finally we determine the position of the critical layer and show its influence when it lies inside the vortex.

Domaines: Mécanique des fluides [physics.class-ph]

Xavier Perrot, Xavier J. Carton. Instability of a two-step Rankine vortex in a reduced gravity QG model. Fluid Dynamics Research, 2014, 46 (3), pp.031417. ⟨10.1088/0169-5983/46/3/031417⟩. ⟨hal-01083758⟩