Two-dimensional turbulence above topography: Vortices and potential vorticity homogenization

Lia Siegelman (Scripps Institution of Oceanography)

Séminaire du LMD à l’ENS.


Date de début 19/12/2023 11:00
Date de fin 19/12/2023
Organisateur LMD
Lieu ENS – salle SERRE • 24, rue Lhomond 75005 PARIS


The evolution of unforced and weakly damped two-dimensional turbulence over random rough topography presents two extreme states. If the initial kinetic energy E is sufficiently high, evolution is determined by the spontaneous formation and mutual interaction of coherent vortices. High-energy vortices roam throughout the domain and mix the background potential vorticity (PV) to homogeneity.

If E is low, then vortices still form but they soon become locked to topographic features: Anticyclones sit above topographic depressions and cyclones above elevated regions. We develop a unified framework of topographic turbulence spanning these two extreme states of low and high energy. A main organizing concept is that PV homogenization demands a particular kinetic energy level E# which is the separator between high-energy evolution and low-energy evolution.

Informations supplémentaires

École normale supérieure
24 rue Lhomond 75005 Paris
Aile Erasme
salle Claude Froidevaux – E314