Interfacial instabilities in exchange flows

This paper reports findings from an experimental study of interfacial instabilities in exchange flow through a channel. Kelvin-Helmholtz instabilities were observed at both ends of the channel while Holmboe instabilities in the middle region. The development of the Holmboe instabilities was controlled by the vertical shift of the density interface from the shear center. The amount of the shift changed during the experiments. Measurements of the lengths and speeds of the Holmboe waves compared well with the linear stability theory. Holmboe waves were stabilized when the bulk Richardson number exceeded about 0.8.