Abstract
In this paper is treated the theory of cyclones from a synoptic point of view. They also shall serves to understanding of the dynamical properties in the baroclinic models in numerical weather prediction.
A model of baroclinic atmosphere adopted in the n umerical weather prediction is assumed.
From the ω-equation in this baroclinic atmosphere the calculation formulae of the vertical current and horizontal divergence are derived by Fjørtoft's numerical integration method.
According to these formulae, th e fitness of Sutcliffe's surface divergence formula is investigated.
We derive the difference approximative formula of surface divergence shown by the weighted difference between the upper and the lower divergence both multiplied by respective constants, which is called weighted relative divergence in this paper.
On the basis of these formulae, two theori e s of surface cyclone development are derived.
The one theory describes the relations between the inclination of the axis of low pressure with heights and the development of cyclones.
The other theory considers the problems concerning to the life history of cyclones, i. e. the formation, development and decay of cyclones.
