JET DETRAINMENT AT A STRATIFIED INTERFACE

Using laboratory water-tank experiments, detrainment from a vertical j et rising through a density interface is explored. The experiments rev eal that detrainment only occurs for a specific range of two governing parameters, the Richardson number associated with the vortices and th e normalized interface height. The shape of the detrainment domain is explained with simple physical arguments involving velocity gradients, baroclinic torques between the pure unmixed fluid and the environment , and baroclinic torques between the mixed fluid and the surrounding f luid. Detrainment is only observed when the penetrating jet consists o f fluid with two different densities.