Year: 2026
Type: preprint
Abstract: Wave-mean flow interactions in stratified fluids can drive spontaneous oscillations, yet the mechanisms controlling transitions between periodic and chaotic regimes remain poorly understood. Using a minimal one-dimensional model of wave-driven mean-flow reversals motivated by the quasi-biennial oscillation (QBO), we identify two distinct mechanisms that suppress the formation of multiple extrema in the velocity profile: critical-level momentum deposition by a broad spectrum of undamped small-scale gravity waves, and wave-amplitude growth due to exponential density stratification. Although physically distinct, both mechanisms inhibit the route to chaos and reduce sensitivity to small-scale viscosity, substantially widening the region of periodic behavior in parameter space. These results identify a general internal mechanism for the stabilization of wave-driven oscillations, with direct implications for QBO-like phenomena in geophysical and astrophysical flows.
Source: arXiv (Cornell University)
Institutions: École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Paris Sciences et Lettres, École Normale Supérieure - PSL, Laboratoire de Météorologie Dynamique, Laboratoire de Physique de l'ENS de Lyon, Université du Québec à Rimouski, Institut des sciences de la mer
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
Awards: Avancées fondamentales pour la modélisation des processus clés pour la réduction des impacts des changements climatiques, Boundaries, Congestion and Vorticity in Fluids: A connection with environmental issues, G6268741103, G7080048889, CONsolidating DemOcRacy: Choosing an Electoral method Transparently
OpenAlex ID: W7224829192