On the Vertical Velocity Field in a Steady Symmetric Hurricane

It is shown how a system of equations (motion, mass continuity and the first law of thermodynamics) can be integrated for a steady symmetric vortex with a prescribed tangential motion. The method of characteristics is used to obtain a solution for the vertical-velocity field. For the normally observed characteristic lines in a hurricane no vertical velocity is possible for a frictionless atmosphere, and therefore numerical experiments are carried out with different magnitudes of the momentum exchange coefficients. It is also shown that as long as the ratio of the lateral and the vertical exchange coefficients is kept fixed, one calculation of the vertical velocity field enables an examination of a wide range of variation of the individual coefficients. A consistent structure of an Atlantic hurricane is constructed from the National Hurricane Research Project data.