TY - JOUR
T1 - A mechanism of formation of multiple zonal jets in the oceans
AU - Berloff, P.
AU - Kamenkovich, I.
AU - Pedlosky, J.
N1 - Funding Information:
Funding for PB was provided by NSF grants OCE 0344094 and OCE 0725796 and by the research grant from the Newton Trust of the University of Cambridge. Funding for IK was provided by NSF grants OCE 0346178 and 0749722. Funding for JP was provided by NSF grant OCE 0451086. We are grateful for the constructive comments of the anonymous reviewers that led to significant improvement of this paper.
PY - 2009
Y1 - 2009
N2 - Multiple alternating zonal jets observed in the ocean are studied with an idealized quasigeostrophic model of flow in a zonal channel. The jets are maintained by the eddies generated by the imposed, supercritical background flow. The formation, nonlinear dynamics and equilibration of the jets are explained in terms of linear stability arguments and nonlinear self-interactions of the linear eigenmodes. In the proposed mechanism, energy of the background flow is released to the primary instability mode with long meridional and short zonal length scales. This mode undergoes secondary, transverse instability that sets the meridional scale of the emerging multiple zonal jets. This instability channels energy into several weakly damped zonal eigenmodes that amplify the jets. The emerging jets feed back on the instabilities through the partial meridional localization of the most unstable eigenmodes.
AB - Multiple alternating zonal jets observed in the ocean are studied with an idealized quasigeostrophic model of flow in a zonal channel. The jets are maintained by the eddies generated by the imposed, supercritical background flow. The formation, nonlinear dynamics and equilibration of the jets are explained in terms of linear stability arguments and nonlinear self-interactions of the linear eigenmodes. In the proposed mechanism, energy of the background flow is released to the primary instability mode with long meridional and short zonal length scales. This mode undergoes secondary, transverse instability that sets the meridional scale of the emerging multiple zonal jets. This instability channels energy into several weakly damped zonal eigenmodes that amplify the jets. The emerging jets feed back on the instabilities through the partial meridional localization of the most unstable eigenmodes.
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U2 - 10.1017/S0022112009006375
DO - 10.1017/S0022112009006375
M3 - Article
AN - SCOPUS:67650908758
VL - 628
SP - 395
EP - 425
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
SN - 0022-1120
ER -