Abstract
Solving barotropic vorticity equation, the motion of a disturbance of typhoon-type is treated. First, solving barotropic vorticity equation, the deformation of an initially circular disturbance in a changing basic flow with constant shear is treated. Second, the velocity components are given by U+εy0+β/C, V, where U and V are uniform basic flow, ε is constant shear of the basic field, y0 is the northward component of the coordinates of the centre, β is the latitudinal variation of Coriolis factor, C is a negative constant concerned with the scale of the disturbance. Third, equations of motion of the disturbance are obtained. Fifth, the calculated periods and amplitudes of meandering motion are compared with those of actual typhoons.
