The purpose of this chapter is to discuss certain disturbances around the pole of a Venus–type planet that result as a response to barotropic instability processes in a zonal flow. We discuss a linear instability of normal modes in a zonal flow through the barotropic vorticity equations (BVEs). By using a simple idealization of a zonal flow, the instability is employed on measurements of the upper atmosphere of Venus. In 1998, the tropical cyclone Mitch gave way to the observational study of a dipole vortex. This dipole vortex might have helped to intensify the cyclone and moved it towards the SW. In order to examine this process of interaction, the nonlinear BVE was integrated in time applied to the 800–200 hPa average layer in the previous moment when it moved towards the SW. The 2‐day integrations carried out with the model showed that the geometric structure of the solution can be calculated to a good approximation. The solution HLC moves very fast westwards as observed. On October 27, the HLA headed north‐eastward and then became quasi‐stationary. It was also observed that HLA and HLC as a coupled system rotates in the clockwise direction.
Part of the book: Vortex Structures in Fluid Dynamic Problems