A new large scale instability in rotating stratified fluids driven by small scale forces

摘要

In this paper, we find a new large scale instability displayed by astratified rotating flow in forced turbu- lence. The turbulence is generated bya small scale external force at low Reynolds number. The theory is built on therigorous asymptotic method of multi-scale development. There is no otherspecial constraint concerning the force. In previous papers, the force waseither helical or violating parity invariance. The nonlinear equations for theinstability are obtained at the third order of the perturbation theory. In thisarticle, we explain a detailed study of the linear stage of the instability.