Rossby waves past the breaking point in zonally dominated turbulence

• DOI: 10.1017/jfm.2023.90
• Publication Date: 2023-03-06T08:39:38Z
• Authors: Norman M. Cao
• Keywords: Barotropic fluid; Rossby number; Wave turbulence; Intermittency; Geophysical fluid dynamics

The spontaneous emergence of structure is a ubiquitous process observed in fluid and plasma turbulence. These structures typically manifest as flows which remain coherent over range spatial temporal scales, resisting statistically homogeneous description. This work conducts computational theoretical study coherence turbulent the stochastically forced barotropic $\beta$ -plane quasi-geostrophic equations. equations serve prototypical two-dimensional model for Jovian atmospheres, can also be extended to magnetically confined fusion plasmas. First, analysis direct numerical simulations demonstrates that significant fraction flow energy organized into large-scale Rossby wave eigenmodes, comparable with total zonal flows. A characterization given eigenmodes nearly integrable perturbations Lagrangian trajectories, linking finite-dimensional deterministic Hamiltonian chaos plane laminar-to-turbulent transition. Poincaré section reveals induced by plus waves exhibit localized chaotic regions bounded invariant tori, manifesting breaking absence critical layers. It argued surviving tori organize single temporally zonally varying laminar flow, suggesting form self-organization stability account resilience large-amplitude waves.