Project on Group Velocity Critical Layers
The goal of the project on group velocity critical layers is to understand the growth of Rossby waves encountering flow opposing their group velocity. This occurs in various regions including the tropical trade winds and the Hadley circulation and can lead to both growth and reflection of the impinging waves.
Farrell, B. and I. Watterson, 1985. Rossby waves in opposing currents. J. Atmos. Sci., 42, 1746-1756. pdf