Mean flow generation in rotating anelastic two-dimensional convection

TL;DR

This paper explores how mean flows are generated in rotating anelastic convection, focusing on the effects of stratification and the mechanisms driving zonal and meridional flows.

Contribution

It combines numerical analysis of convection onset with investigation of flow-driving mechanisms in a rotating, stratified environment.

Findings

Stratification influences the symmetry of convection onset.

Reynolds stresses can generate systematic mean flows.

Stratification affects the coherence of the flows.

Abstract

We investigate the processes that lead to the generation of mean flows in two-dimensional anelastic convection. The simple model consists of a plane layer that is rotating about an axis inclined to gravity. The results are two-fold: firstly we numerically investigate the onset of convection in three-dimensions, paying particular attention to the role of stratification and highlight a curious symmetry. Secondly, we investigate the mechanisms that drive both zonal and meridional flows in two dimensions. We find that, in general, non-trivial Reynolds stresses can lead to systematic flows and, using statistical measures, we quantify the role of stratification in modifying the coherence of these flows.