Quantitative time-dependent laboratory measurements are made of the irreversible mixing caused by the development, saturation and turbulent breakdown of Kelvin-Helmholtz (KH) billows in an initially stable two-layer stratified shear flow of miscible fluids. The measurements are obtained using a light attenuation technique. Irreversible mixing is found to be strongly dependent on the life-cycle of the flow, in particular the characteristics of large-scale, quasi-two-dimensional billow merging events, which stir the flow and then trigger mixing during turbulent transition.
Patterson, M. D., Caulfield, C. P., McElwaine, J. N., & Dalziel, S. B. (2006). Time-dependent mixing in stratified Kelvin-Helmholtz billows: Experimental observations. Geophysical Research Letters, 33, [L15608]. https://doi.org/10.1029/2006GL026949