Analysis of various large-scale disturbances and the associated zonal mean motions in the atmosphere

Summary In this article, we present a scale analysis of planetary waves, extended long waves, and long waves. (We mean the extended long waves to be the disturbances whose east-west length is of order 10⁶ m and north-south extension 10⁷ m). We find for the extended long waves the two terms, the interaction between kinetic and available potential energy of the disturbances, and the interaction between the zonal mean available potential energy, and the eddy available potential energy, are of two orders of magnitude larger than the kinetic energy interaction between the disturbances and the associated zonal mean flow. This theoretical result concerning the relative importance of the various interaction terms may be of use in explaining the observational findings thus far available.It is also shown theoretically that the kinetic energy interaction between the planetary waves, the horizontal size of which is 10⁷ m, and the long waves, whose horizontal size is 10⁶ m, is of the same order as the interaction of kinetic energy between the zonal mean motion and the disturbances. This agrees fairly well with the observational estimates thus far obtained.