Bottom gravity currents and stratified exchange flows in a rotating channel

Large-scale laboratory experiments on bottom gravity currents and stratified exchange flows have been conducted at the CNRS Coriolis Rotating Platform at LEGI. Both rotating and non-rotating experiments were performed in a trapezoidal cross section channel and different configurations were considered by varying both the upper fresh water volume fluxes and the channel rotation rates. Detailed velocity fields were measured by 2D Particle Image Velocimetry in different vertical planes spanning the width of the channel. Results highlight the role that both ambient rotation and net-barotropic forcing have on the geostrophic adjustment of the dense outflowing. As the rotation rate increases, the tilt of the interface between lower salty and upper fresh water flow increases, generating a meandering pattern within the salty layer along the trapezoidal channel.