The Spiral Bands of a Hurricane: A Possible Dynamic Explanation

Abstract

In this paper an attempt is made to explain the shape and behavior of the spiral bands of a hurricane. The main hypothesis is that the bands are associated with gravitational waves of finite amplitude propagating at. the interface of a high-level inversion. An external source of disturbance is postulated in the form of a fresh surge of air at the exterior region of the hurricane. It is shown that this mechanism leads to the formation of bands of the required shape. The spiral bands are therefore related to the squall lines of temperate latitudes. Two numerical examples are worked out to illustrate the proposed mechanism.