On the Development of the Relatively Small Scale Cyclone due to the Release of Latent Heat by Condensation

Abstract

he problem of development of the relatively small scale cyclone (whose characteristic horizontal scale has the order of magnitude of hundred kilometers) is investigated from the standpoint of the effect of latent heat released by condensation through the process of convective action.
The appearance of region of hyperbolicity in the so-called ω-equation in balance system or predominancy of very small waves in the solution of primitive equations of motion is avoided by treating the contribution of non-adiabatic heating as a force from outside for ω-equation as proposed by Ooyama (1963).
The growth rate of disturbance is obtained analytically in the case of linear problem and also by means of numerical method as a non-linear problem. Comparisons between the growth rates in both cases and discussions on the results are given. Both results indicate that the most favorable wave lengths for development are found in several hundred kilometers.
The problem of supply of water vapor from outside is studied, although the dissipation at ground is not taken into account. Suggestion to the control of development of low is proposed and examined in connection with the supply of water vapor.