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dc.contributor.authorLemasquerier, Daphné
dc.contributor.authorFavier, B.
dc.contributor.authorLe Bars, M.
dc.identifier.citationLemasquerier , D , Favier , B & Le Bars , M 2021 , ' Zonal jets at the laboratory scale : hysteresis and Rossby waves resonance ' , Journal of Fluid Mechanics , vol. 910 , A18 . ,
dc.identifier.otherORCID: /0000-0002-9795-6214/work/119212654
dc.descriptionThe authors acknowledge funding by the European Research Council under the European Union's Horizon 2020 research and innovation program through grant number 681835-FLUDYCO-ERC-2015-CoG.en
dc.description.abstractThe dynamics, structure and stability of zonal jets in planetary flows are still poorly understood, especially in terms of coupling with the small-scale turbulent flow. Here, we use an experimental approach to address the questions of zonal jets formation and long-term evolution. A strong and uniform topographic β -effect is obtained inside a water-filled rotating tank thanks to the paraboloidal fluid free upper surface combined with a specifically designed bottom plate. A small-scale turbulent forcing is performed by circulating water through the base of the tank. Time-resolving particle image velocimetry measurements reveal the self-organization of the flow into multiple zonal jets with a strong instantaneous signature. We identify a subcritical bifurcation between two regimes of jets depending on the forcing intensity. In the first regime, the jets are steady, weak in amplitude, and directly forced by the local Reynolds stresses due to our forcing. In the second one, we observe highly energetic and dynamic jets of width larger than the forcing scale. An analytical modelling based on the quasi-geostrophic approximation reveals that this subcritical bifurcation results from the resonance between the directly forced Rossby waves and the background zonal flow.
dc.relation.ispartofJournal of Fluid Mechanicsen
dc.subjectQuasi-geostrophic flowsen
dc.subjectWaves in rotating fluidsen
dc.subjectQC Physicsen
dc.subjectAtmospheric Scienceen
dc.subjectMechanical Engineeringen
dc.titleZonal jets at the laboratory scale : hysteresis and Rossby waves resonanceen
dc.typeJournal articleen
dc.contributor.institutionUniversity of St Andrews. Applied Mathematicsen
dc.description.statusPeer revieweden

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