Self-Replicating Three-Dimensional Vortices in Neutrally-Stable Stratified Rotating Shear Flows

TL;DR

This paper discovers a novel instability in rotating stratified shear flows that leads to self-replicating 3D vortices, forming persistent, space-filling vortex lattices with implications for astrophysical and geophysical flows.

Contribution

It reveals a new instability mechanism causing self-similar vortex replication in stable stratified shear flows, previously unreported in the literature.

Findings

Instability originates from a critical layer that excites vortices.

Vortices self-replicate to form stable, space-filling lattices.

The phenomenon occurs in both laboratory and astrophysical flow conditions.

Abstract

A previously unknown instability creates space-filling lattices of 3D vortices in linearly-stable, rotating, stratified shear flows. The instability starts from an easily-excited critical layer. The layer intensifies by drawing energy from the background shear and rolls-up into vortices that excite new critical layers and vortices. The vortices self-similarly replicate to create lattices of turbulent vortices. The vortices persist for all time. This self-replication occurs in stratified Couette flows and in the dead zones of protoplanetary disks where it can de-stabilize Keplerian flows.