On generation of zonal flows by interacting Rossby waves

Generation of zonal flows by Rossby waves in the atmosphere

A novel mechanism for the short-scale Rossby waves interacting with long-scale zonal flows in the Earth’s atmosphere is studied. The model is based on the parametric excitation of convective cells by finite amplitude Rossby waves. We use a set of coupled equations describing the nonlinear interaction of Rossby waves and zonal flows which admits the excitation of zonal flows. The generation of s...

Stochastic Confinement of Rossby Waves by Fluctuating Eastward Flows

Rapid beat generation of large-scale zonal flows by drift waves: a nonlinear generic paradigm.

The generalized Charney-Hasegawa-Mima equation is unstable to a four wave modulational instability whereby a coherent, monochromatic drift wave can drive a band of modes and associated zonal flows unstable. Although initially the fastest growing modes dominate, a secondary nonlinear instability later drives the longest wavelength zonal flow and its associated sidebands at twice the growth rate ...

Numerical Experiments on the Generation of Normal Mode Rossby Waves

s Normal mode Rossby waves are simulated with an efficient Double Fourier Series (DFS) spectral model, and their structures are investigated by the Empirical Orthogonal Function (EOF) analysis. By selecting appropriately the wave-vector component for EOF analysis among the geopotential height and velocity fields of wavenumber one, it was possible to get the EOFs from the time series data whose ...

Propagation of Rossby Waves in Stratified Shear Flows

A study is made of the propagation of Rossby waves in a stably stratified shear flows. The wave equation for the Rossby waves is derived in an isothermal atmosphere on a beta plane in the presence of a latitudinally sheared zonal flow. It is shown that the wave equation is singular at five critical levels, but the wave absorption takes place only at the two levels where the local relative frequ...