Acoustic-gravity nonlinear structures
- 1Institute of Physics, P.O. Box 57, Yu-11001 Belgrade, Yugoslavia
- 2Department of Plasma Physics, Umeå University, S-90187 Umeå, Sweden
- 3Institut fur Theoretische Physik IV, Ruhr-Universitat Bochum, D-44780 Bochum, Germany
Abstract. A catalogue of nonlinear vortex structures associated with acoustic-gravity perturbations in the Earth's atmosphere is presented. Besides the previously known Kelvin-Stewart cat's eyes, dipolar and tripolar structures, new solutions having the form of a row of counter-rotating vortices, and several weakly two-dimensional vortex chains are given. The existence conditions for these nonlinear structures are discussed with respect to the presence of inhomogeneities of the shear flows. The mode-coupling mechanism for the nonlinear generation of shear flows in the presence of linearly unstable acoustic-gravity waves, possibly also leading to intermittency and chaos, is presented.