| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1897721 | Physica D: Nonlinear Phenomena | 2011 | 10 Pages |
We analytically obtain steady isolated zonal jet solutions of the evolution equation of zonal flows on a ββ plane with a homogeneous zonal flow and a small-scale sinusoidal transversal flow in the background, derived by Manfroi and Young (1999) [9]. It is shown that these steady zonal jet solutions are all linearly unstable. Numerical time integrations of the evolution equation also confirm that the perturbed unstable steady solution becomes a uniform flow in the long run. These results suggest that mergers/disappearances of zonal jets superposed upon background forced two-dimensional turbulence on a ββ plane or a rotating sphere might be due to the intrinsic instability of the zonal jets.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Dynamics of zonal flow with a background sinusoidal transversal flow is considered. ► Steady solutions of isolated zonal jets are analytically obtained. ► These steady zonal jet solutions are all linearly unstable. ► The perturbed unstable steady solutions become uniform flows as time goes on. ► Results imply zonal barotropic flow is unstable due to the background turbulence.
