My research employs both theoretical and numerical techniques to study fluid turbulence in the atmosphere and oceans. A major recent thrust has been the study of the statistical nature of the flow as a function of rotation and stratification. The simplifying assumptions employed at larger scales, that rotation and stratification terms in the governing equations are predominant and approximately balanced by other terms, become invalid at smaller scales. The interactions between large-scale vortices and more general turbulent and wave motions are therefore the subject of these studies, as is the effect on the turbulent transport of passive scalars such as pollutants or ozone. A simple example is whether turbulent motions preferentially send energy downscale (as in a breaking wave at the shore) or upscale (as in the merging of two eddies to make a larger one). Both are known to occur, depending on the relative strengths of rotation and stratification. Both must be accounted ! for in coarse-resolution models, such as the ones used for weather and climate studies, but clearly in a different way
