CYCLOGENESIS BY A PURELY MECHANICAL PROCESS

Abstract

In this paper-an attempt is made to study the mechanical influence of a surge of cold air on cyclogenesis. It is assumed that a quasistationary front exists and that cold air starts pushing at the rear of the underlying cool air. It is shown that the cool air acquires an energy which is of the same order of magnitude as the hydro-dynamical energy of the appropriate frontal wave. The suggestion is made that the events which occur in this process are analogous to those which take place in the hydraulic phenomenon known as the ?bore,? and therefore a similar method of analysis is used. An actual example of cyclogenesis associated with a surge of cold air is described, and two other examples are studied for the sake of quantitative comparison with the results computed from one of the equations derived in this work. The ideas upon which the theoretical work has been based seem to agree qualitatively with observation. Quantitative agreement exists as far as orders of magnitude are concerned.