Trajectory analysis of the propagation of Rossby waves on the Earth's delta-surface

The propagation of Rossby waves on the Earth's delta-surface is discussed in a reference frame propagation with the zonal phase speed of the wave. In this reference frame, trajectories and streamlines coincide; the propagation of Rossby waves has a different interpretation than in a reference frame fixed on the ground; and the mechanism for the propagation of Rossby waves depends not only on the different positions of the wave relative to the basic current, but also the variation of beta with latitude (called the delta-effect).