Estuary Model
(Work of Parker MacCready)
Deep sea tides drive stronger tidal velocities in shallow water. Oscillatory lee waves and
transient hydraulic jumps occur near topography. Meanwhile, fresh river flow enters at the
surface of the estuary. There is a mean buoyancy-driven meridional circulation of fresh outflow
above saline inflow. Vertical mixing is enhanced artificially by an air bubbler. Shear
dispersion (the interaction of sheared horizontal current with vertical diffusion) is at work
enhancing the long-channel mixing. Similar dynamics are at work in Puget Sound.