The Effect of Horizontal Divergence and the Latitudinal Variation of the Coriolis Parameter on the Drift of a Model Hurricane

The northward drift of a three-dimensional model hurricane is investigated by long-time numerical integrations of non-divergent and divergent barotropic vortices on a β-plane. Both vortices drifted in a general northward direction at speeds between 1.4 and 2.8 m s−1 during the first 48 hours, a movement similar to that of the model hurricane. An anticyclone developed east of the cyclone in both barotropic models. The combined circulation around the cyclone and anticyclone produced a spiral zone of confluence which extended southeast of the cyclone and resembled a slowly moving spiral band circulation found in the model hurricane experiment. Finally, the effect of closed lateral boundary conditions was to eventually turn the barotropic vortices toward the west.