“(Wave) Turbulence in rotating fluids”

Pierre-Philippe Cortet (Laboratoire FAST, CNRS & Université Paris-Saclay) will present at the 2022 Simons Collaboration on Wave Turbulence Annual Meeting on December 1st and 2nd in New York.

“(Wave) Turbulence in rotating fluids”:

The influence of a global rotation on hydrodynamic turbulence is a key ingredient of geo and astrophysical flows. A consequence of rotation is the emergence of a specific class of waves, called inertial waves, which propagate in the volume of the fluid. Within rotating turbulence, these waves and the classical eddy structures of fluid dynamics can be entangled in different ways leading to several possible regimes: among these, the wave turbulence regime. The theory of wave turbulence applied to the case of inertial waves led to analytical predictions in the early 2000s [1]. Since then, various attempts to discover experimentally this regime have been carried out, with limited success.

In this context, we recently built an original experimental setup that led to the first observation of the inertial wave turbulence regime in a rotating fluid [2]. I will show that the features of our experimental wave turbulence are in quantitative agreement with the theory. This achievement was made possible by the prior discovery of an instability affecting inertial waves, which we named the “quartetic instability”. I will show that the understanding of how to inhibit this instability has been crucial for the observation of the wave turbulence regime [3].

[1] S. Galtier, Weak inertial-wave turbulence theory, Physical Review E, 68, 015301(R) (2003).   
[2] E. Monsalve, M. Brunet, B. Gallet & P.-P. Cortet, Quantitative Experimental Observation of Weak Inertial-Wave Turbulence, Physical Review Letters, 125, 254502 (2020).   
[3] M. Brunet, B. Gallet & P.-P. Cortet, Shortcut to Geostrophy in Wave-Driven Rotating Turbulence: the Quartetic Instability, Physical Review Letters, 124, 124501 (2020).