Abstract
Abstract
Highlights
Rotating turbulent flows are ubiquitous in geophysical and astrophysical systems such as stellar interiors, planetary cores, oceans and atmospheres
We show with direct numerical simulations (DNS) and theoretical analysis that there exists a linear mechanism by which a single inertial wave drives exponential growth of geostrophic modes through near-resonant triadic interaction
By means of numerical simulations and theoretical analysis, we have described a new instability mechanism by which inertial waves excite z-invariant geostrophic modes
Summary
Rotating turbulent flows are ubiquitous in geophysical and astrophysical systems such as stellar interiors, planetary cores, oceans and atmospheres. Recent numerical (Le Reun et al 2017) and experimental (Le Reun, Favier & Le Bars 2019; Brunet, Gallet & Cortet 2020) studies have shown that injecting energy in waves solely creates a turbulent state comprising of inertial waves only when the forcing amplitude is sufficiently small, i.e. a discrete version of inertial wave turbulence (Galtier 2003). The other inviscid mechanism that has been proposed to account for wave-geostrophic transfer is quasi-resonant triadic interaction (Newell 1969; Smith & Waleffe 1999), that is, a triad between waves whose frequencies do not exactly satisfy the resonance condition (Bretherton 1964) Their presence and their role in the bi-dimensionalisation of rotating turbulence have been assessed by several numerical studies (Smith & Lee 2005; Alexakis 2015; Clark di Leoni & Mininni 2016). We show with direct numerical simulations (DNS) and theoretical analysis that there exists a linear mechanism by which a single inertial wave drives exponential growth of geostrophic modes through near-resonant triadic interaction
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
