Demonstrations
 
Anywhere from 10-100+ students
A number of classes at various levels utilize the laboratory for demonstrations.  The graduate GFD theory class includes a sequence of weekly demonstrations taking the students through the basic dynamical sequence: buoyancy, pressure, equation of state, surface- and internal waves, convection, mixing, Taylor-Proudman theory, thermal wind, geostrophic adjustment, Rossby waves, and baroclinic instability.  The introductory undergraduate oceanography class utilizes an estuary model developed in the laboratory.
 
  
Rossby waves in a 1m rotating basin.  A 'north-polar' beta plane.  The waves all originate from the plunger in the lower left, the dominant short waves reach eastward (c.c.) opposite to the westward phase  motion. The potential vorticity ‘elasticity’ prevents mixing of the polar cap ‘ozone hole’ and the waves induce westward (anticyclonic) mean zonal flow at most latitudes.   (Peter Rhines) 

                                                                                                     
 
Ladder instability of a swirling water stream.  A falling stream of water is given some rotation and excited by plucking a piano wire in contact with the apparatus.  Strobe photography reveals a double-jet profile which develops this instability.  (Greg Balle) 

Toroidal vortices.  The famous Taylor-Couette experiment is repeated with a density stratified fluid.  Here, an inner cylinder rotates while the visible outer cylinder is at rest.  The interior circular flow is unstable and forms a regular pattern of doughnut shaped overturning circulations.  (Brian Strully)

 

Tidal estuary. A two-dimensional model of an estuary driven by tides at the right end, and by river inflow from the the left. This is a 2m long region connected  with an ocean box. It combines hydraulics and lee gravity waves  Tidal mixing amplifies the strength of the overturning circulation (right at top, left at bottom) by a factor of 10 to 50. This keeps shallow estuaries much cleaner than without mixing.  With a shallow sill (here, as at Admiralty Inlet, the entrance to Puget Sound, Washington) the deep sea fluid enters the estuary at neap (weak) tides, while strong, spring tides do so much mixing at the sill that the deep water is diluted, and flows out at shallower level.  This creates a multi-level estuarine overturning circulation. (Parker MacCready)