Turbulence, waves, and jets in a differentially heated rotating annulus experiment

Abstract

A characteristic function to estimate the longitudinal dispersion coefficient in surface water flows over porous media Phys. Fluids 24, 046602 (2012) Frequency and damping of non-axisymmetric surface oscillations of a viscous axisymmetric liquid bridge Phys. Fluids 24, 042103 (2012) Nonlinear resonance in barotropic-baroclinic transfer generated by bottom sills Phys. Fluids 24, 046601 (2012) We report an analog laboratory study of planetary-scale turbulence and jet formation. A rotating annulus was cooled and heated at its inner and outer walls, respectively, causing baroclinic instability to develop in the fluid inside. At high rotation rates and low temperature differences, the flow became chaotic and ultimately fully turbulent. The inclusion of sloping top and bottom boundaries caused turbulent eddies to behave like planetary waves at large scales, and eddy interaction with the zonal flow then led to the formation of several alternating jets at mid-depth. The jets did not scale with the Rhines length, and spectral analysis of the flow indicated a distinct separation between jets and eddies in wavenumber space, with direct energy transfer occurring nonlocally between them. Our results suggest that the traditional "turbulent cascade" picture of zonal jet formation may be an inappropriate one in the geophysically important case of large-scale flows forced by differential solar heating.

Saturn Atmospheric Structure and Dynamics

“…However, other cloud-level sources of turbulence, such as thunderstorms, might be capable of generating the observed fluxes. Indeed laboratory studies of geostrophic turbulence on a -plane, dominated either by baroclinic instabilities (Bastin and Read 1998;Wordsworth et al 2008) or unstablystratified convection (Condie and Rhines 1994;Read et al 2004Read et al , 2007, show a strong tendency to develop eddy-driven barotropic jets, so the question as to which process dominates on the gas giant planets must remain open until further evidence on the respective characteristics of baroclinic instability and deep convection becomes available.…”

A rotating annulus driven by localized convective forcing: a new atmosphere-like experiment

“…Thus, this setup has proven to be a simple enough system to capture the fundamental physics and with enough complexity to represent nonlinear features and transition sequences to chaos similar to those of atmospheric dynamics (Hignett et al 1985;Früh and Read 1997;Bastin and Read 1998;Read 2003;Von Larcher and Egbers 2005;Wordsworth et al 2008;Vincze et al 2014). It has also proved valuable as a tractable 'test bed' within which to test numerical codes and methods (Harlander et al 2011;Vincze et al 2015) as well as to benchmark statistical-dynamical analysis methods in widespread use in meteorology, such as data assimilation (Young and Read 2013).…”

An experimental study of regime transitions in a differentially heated baroclinic annulus with flat and sloping bottom topographies

“…More recently, laboratory experiments have been conducted in a similar configuration by Wordsworth et al (2008) to elucidate the dynamics of the turbulent regime characterized by large Taylor and low thermal Rossby numbers. There, the sloping boundaries were found to excite turbulent eddies that produce multiple alternating jet structures (also reported by Mason, 1975) via interaction with the zonal mean flow.…”