Claes G. H. Rooth, professor emeritus at the University of Miami's Rosenstiel School of Marine and Atmospheric Science (RSMAS), died in Falmouth, Mass., on 17 January 2011. Claes's research focused on oceanic and atmospheric dynamics. He was a pioneer in the application of theoretical fluid mechanics to the oceanic and atmospheric sciences, and he played a major role in the development of numerical ocean circulation and coupled climate models. Claes possessed an unusually broad knowledge of oceanic and atmospheric sciences. His research activities included studies of the ventilation of deep ocean basins by convective overturning; studies of intensive air-sea interactions in coastal regions; the use of transient tracers to understand general circulation in the oceans; and the integration of the fields of physical oceanography with those of marine chemistry, biology, and fisheries.