Fluid Mechanics Webinars: Basile Gallet talk video

Speaker: Basile Gallet, CEA, Université Paris-Saclay, France

Title: A scaling theory for meridional heat transport in oceans and planetary atmospheres

Video: cambridge.org/fluidwebinar/gallet

Abstract: Developing a theory of climate requires an accurate parameterization of the transport induced by turbulent eddies. A major source of turbulence in the mid-latitude planetary atmospheres and oceans is the baroclinic instability of the large-scale flows. I will introduce idealized models of planetary atmospheres and oceanic currents, before presenting a physically based scaling theory that quantitatively predicts the turbulent diffusivity, eddy kinetic energy and mixing length of baroclinic turbulence as a function of the large-scale flow characteristics, the bottom friction and the curvature of the planet (through beta). I will then use the theory as a quantitative parameterization in the case of meridionally dependent forcing, in the fully turbulent regime. Beyond its relevance for climate theories, this work is an intriguing example of a successful closure for a fully turbulent flow.