Prof. Hart’s research focused on modeling of motions in planetary atmospheres and oceans, and the use of microgravity laboratory experimentation to address critical issues in these fields. Of particular current interest is the transition to chaos in stably stratified rotating fluids subject to baroclinic instability, and the extraction of low order dynamics from fully resolved numerical, as well as laboratory, experiments. Thermal convection with rapid rotation is also being explored with computer simulation and laboratory experiments. He is using both techniques to look for possible processes responsible for planetary jets. Hart has served as associate editor of Geophysical and Astrophysical Fluid Dynamics and the Journal of the Atmospheric Sciences, and was on the editorial board of Dynamics of Atmospheres and Oceans.