Two-dimensional turbulent flows on the surface of a rotating sphere reveal familiar Rossby-Haurwitz waves even when forced randomly on small scales. The accumulation of energy on large scales due to the inverse cascade leads to a new phenomenon, the emergence of a new class of nonlinear non-dispersive waves termed zonons. When the forcing is switched off, the Rossby-Haurwitz waves lose substantial part of their energy while zonons preserve their identity, phase speed and the energy level. Further analysis indicates that zonons are maintained and guided by the meridional shear of the zonal velocity, i.e., they reveal the attributes of the solitary waves or, briefly, Rossby solitons. Zonons are the medium that carries out the energy transfer between the zonal jets and eddies thus suggesting that there exists symbiosis between the jets and eddies in jet flows with inverse energy cascade and anisotropic dispersive waves. These results point out to the necessity of re-evaluation of the paradigm of jets-eddy dynamics in beta-plane turbulence.
|Original language||English GB|
|State||Published - 1 Dec 2011|
- 4455 NONLINEAR GEOPHYSICS / Nonlinear waves
- shock waves
- 4490 NONLINEAR GEOPHYSICS / Turbulence
- 4528 OCEANOGRAPHY: PHYSICAL / Fronts and jets
- 4554 OCEANOGRAPHY: PHYSICAL / Planetary waves