| Citation | Distinguished for his fundamental theoretical research in geophysical fluid dynamics and its application to the dynamics of the atmosphere. His contributions to the theory of stratified rotating fluid flow and the associated waves and instabilities have led to a unified view of the interaction of waves and mean flows. The theory has been used to illuminate a number of diverse phenomena, including Langmuir circulations, nonlinear baroclinic instabilities, stratospheric sudden warmings, and the 26-monthly cycle in the equatorial stratosphere. His work is widely regarded as seminal to the development of our present understanding of stratospheric dynamics and tracer transport, and has been recognized by the award of the Rossby Research Medal, the highest honour of the American Meteorological Society. |