[PAOCQ] John Wettlaufer (Yale)

“Turbulent thermal convection after all these years: controversy, simplicity and stochasticity”

Although it is a scientific cliché to state that buoyancy driven convection is ubiquitous in earth, engineering and planetary fluids, the simplest system used to explain it—Rayleigh-Bénard convection (RBC)—remains a hotbed of controversy.  Indeed, the nature of turbulent thermal convection in a well-controlled box, the experimental and mathematical framework of which has not changed since 1919, is vastly simpler than what occurs in the natural environment, and yet there is no uniform consensus regarding the behavior within it.  What is agreed upon is that the thermal boundary layers (BLs) are central to the transport in RBC.  Firstly, I will describe the controversy and the present state of play.  Secondly, in part because of location of my audience, I will advocate for the value of specific forms of the stochastic Lorenz equations (a severe Galerkin-truncation of the Oberbeck-Boussinesq equations describing RBC) in addressing key questions that have experimental reality, particularly the mean wind reversals in the experiments of Sreenivasan et al. Phys. Rev. E 65 056306 (2002).

PAOC Colloquium —

Interdisciplinary seminar series that brings together the whole PAOC (Program in Atmospheres, Oceans, and Climate) community. Seminar topics include all research concerning the physics, chemistry, and biology of the atmospheres, oceans and climate, as well as talks about societal impacts of climatic processes.

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