ABSTRACT We consider the behaviour of Alfvén waves propagating in a medium with random density perturbations. The imposed perturbations have broad-band spectrum and their characteristic spatial scale may be defined according to peak spectrum. interaction boundary driven generates reflections most efficiently when wavelength is comparable For our monotonic driver, this leads generation quasi-per...

We consider wave generation by turbulent convection in a plane parallel, stratified atmosphere that sits in a gravitational field, g. The atmosphere consists of two semi-infinite layers, the lower adiabatic and polytropic and the upper isothermal. The adiabatic layer supports a convective energy flux given by mixing length theory; Fe ""'pv~, where pis mass density and v8 is the velocity of the ...

In both the ocean and the atmosphere, the interaction of a density stratified flow with topography can generate large-amplitude, horizontally propagating internal solitary waves. Often these waves are observed in regions where the waveguide properties vary in the direction of propagation. In this article we consider nonlinear evolution equations of the Kortewegde Vries type, with variable coeff...

Propagation of transition fronts in models of coupled oscillators with non-degenerate on-site potential is usually considered in terms of travelling waves. We show that the system dynamics can be reformulated as an implicit map structure, and the travelling waves correspond to stable fixed points. Therefore, the loss of stability of such waves should follow well-known generic bifurcation scenar...

Considering gravitational waves propagating on the most general 4+N -dimensional space-time, we investigate the effects due to the N extra dimensions on the fourdimensional waves. All wave equations are derived in general and discussed. On Minkowski4 times an arbitrary Ricci-flat compact manifold, we find: a massless wave with an additional polarization, the breathing mode, and extra waves with...