NPG Nonlinear Processes in Geophysics NPG Nonlin. Processes Geophys. 1607-7946 Copernicus Publications Göttingen, Germany 10.5194/npg-11-241-2004 Generation of zonal flows by Rossby waves in the atmosphere Onishchenko O. G. 1 Pokhotelov O. A. 1 Sagdeev R. Z. 2 Shukla P. K. 3 Stenflo L. 4 Institute of Physics of the Earth, 12 3810 Moscow, 10 B. Gruzinskaya Str., Russia Department of Physics, University of Maryland, College Park, Maryland 20 740, USA Institut für Theoretische Physik IV, Fakultät für Physik und Astronomie, Ruhr-Univ. Bochum, D-44780 Bochum, Germany Department of Plasma Physics, Umeå University S-90 187 Umeå, Sweden 14 04 2004 11 2 241 244 Copyright: © 2004 O. G. Onishchenko et al. 2004 This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License. To view a copy of this licence, visit https://creativecommons.org/licenses/by-nc-sa/2.5/ This article is available from https://npg.copernicus.org/articles/11/241/2004/npg-11-241-2004.html The full text article is available as a PDF file from https://npg.copernicus.org/articles/11/241/2004/npg-11-241-2004.pdf

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 such flows is due to the Reynolds stresses of the finite amplitude Rossby waves. It is found that the wave vector of the fastest growing mode is perpendicular to that of the pump Rossby wave. We calculate the maximum instability growth rate and deduce the optimal spatial dimensions of the zonal flows as well as their azimuthal propagation speed. A comparison with previous results is made. The present theory can be used for the interpretation of existing observations of Rossby type waves in the Earth's atmosphere.