Wave-averaged balance: a simple example
Atmospheric and Oceanic Physics
2021-01-27 v3 Fluid Dynamics
Abstract
In the presence of inertia-gravity waves, the geostrophic and hydrostatic balance that characterises the slow dynamics of rapidly rotating, strongly stratified flows holds in a time-averaged sense and applies to the Lagrangian-mean velocity and buoyancy. We give an elementary derivation of this wave-averaged balance and illustrate its accuracy in numerical solutions of the three-dimensional Boussinesq equations, using a simple configuration in which vertically planar near-inertial waves interact with a barotropic anticylonic vortex. We further use the conservation of the wave-averaged potential vorticity to predict the change in the barotropic vortex induced by the waves.
Cite
@article{arxiv.2003.03389,
title = {Wave-averaged balance: a simple example},
author = {Hossein A. Kafiabad and Jacques Vanneste and William R. Young},
journal= {arXiv preprint arXiv:2003.03389},
year = {2021}
}