Somme Characteristic Features of Barotropic Disturbances

Abstract

Using the non-dimensional barotropic vorticity equation, various aspects of barotropic disturbances are investigated. First we obtained the criterion for similarity of two kinds of barotropic motions, and compared with two wave systems, one has characteristic quantities of the disturbances in the actual atmosphere and the other has those in a model tank. Second, general nature of the pattern of the disturbance is discussed by expanding the non-dimensional stream function in the power series of non-dimensional time. The timely change of the kinetic energy is also treated similarly. Third, general characters of disturbances in a closed zonal belt is discussed. Fourth, to make the general discussion on the disturbances in a closed zonal belt concretely, a simple disturbance in a jet-like zonal basic flow which was similar type was treated by Kuo. Expanding all quantities in power series of non-dimensional time, the velocity and energy of the mean zonal flow are calculated up to the terms of fourth derivative. The increase or decrease of the kinetic energy of the disturbance is investigated also up to the fourth derivative of time. The change in the profile of the mean zonal flow is also treated.