Freddy Bouchet (Laboratoire de Physique, École Normale Supérieure de Lyon). Large deviation theory applied to turbulent flows and climate physics, a new frontier of statistical physics.

We will review some of the recent developments in the theoretical aspects of the non-equilibrium statistical mechanics of climate dynamics. At the intersection between statistical mechanics, turbulence, and geophysical fluid dynamics, this field is a wonderful new playground for theoretical physics involving tools from statistical physics: large deviation theory, path integrals, and diffusion Monte-Carlo algorithms. We will discuss two classes of applications. First extreme heat waves as an example of a rare events with huge impacts. Second rare trajectories that suddenly drive the complex turbulent dynamical system from one attractor to a completely different one, in the stochastic barotropic quasigeostrophic equation that describe turbulent jet dynamics. Relation with instanton theory and effective models of first order transitions and their transition rates will be emphasized.

Authors: Freddy Bouchet, Cesare Nardini, Joran Rolland, Eric Simonnet and Tomas Tangarife