Abstract
In the present paper, the motion of tropical cyclones in a circular or hyperbolic flow of uniform vorticity is treated.
The motion in a linear flow is also dealt with for the sake of comparison with the other results of the author and others.
The quantitative formulation of the steering principle is attempted. The motion will trace a trochoid in a linear flow, an epicyclic in a circular flow and a similar motion to the former two in a hyperbolic flow.
The amplitude an d period of oscillation depend on the wind speed of the basic current and on the size and intensity of the storm and not on the Coriolis parameter. Both the speed and direction of a tropical cyclone is considerably affected by its oscillating motion. Also, the storm will sometimes describe a loop path as a result of the oscillation.