Transport and emergent stratification in the equilibrated Eady model: the vortex-gas scaling regime
Name
2202.02755.pdf
Description
Accepted version
Size
1.08 MB
Format
Adobe PDF
Checksum (MD5)
b2eaf7c601c8ab9917841b623da19224
Author(s)
Gallet, Basile
Miquel, Benjamin
Hadjerci, Gabriel
Burns, Keaton J
Flierl, Glenn R
Ferrari, Raffaele
Date Issued
2022
Journal
Journal of Fluid Mechanics
Publisher
Cambridge University Press (CUP)
Citation
Gallet, Basile, Miquel, Benjamin, Hadjerci, Gabriel, Burns, Keaton J, Flierl, Glenn R et al. 2022. "Transport and emergent stratification in the equilibrated Eady model: the vortex-gas scaling regime." Journal of Fluid Mechanics, 948.
Version
Author's final manuscript
Abstract
We numerically and theoretically investigate the Boussinesq Eady model, where a rapidly rotating density-stratified layer of fluid is subject to a meridional temperature gradient in thermal wind balance with a uniform vertically sheared zonal flow. Through a suite of numerical simulations, we show that the transport properties of the resulting turbulent flow are governed by quasigeostrophic (QG) dynamics in the rapidly rotating strongly stratified regime. The ‘vortex gas’ scaling predictions put forward in the context of the two-layer QG model carry over to this fully three-dimensional system: the functional dependence of the meridional flux on the control parameters is the same, the two adjustable parameters entering the theory taking slightly different values. In line with the QG prediction, the meridional heat flux is depth-independent. The vertical heat flux is such that turbulence transports buoyancy along isopycnals, except in narrow layers near the top and bottom boundaries, the thickness of which decreases as the diffusivities go to zero. The emergent (re)stratification is set by a simple balance between the vertical heat flux and diffusion along the vertical direction. Overall, this study demonstrates how the vortex-gas scaling theory can be adapted to quantitatively predict the magnitude and vertical structure of the meridional and vertical heat fluxes, and of the emergent stratification, without additional fitting parameters.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1017/JFM.2022.501
