A device for physical simulation of the atmosphere, using water or other liquids as the working fluid. Classical examples are 1) rotating tanks colloquially called dishpans, to simulate long waves in the general circulation; 2) turbulence tanks to simulate boundary layer evolution and convective thermals; and 3) towing tanks to simulate pollutant dispersion associated with mean flow about an obstacle. Because of tank size limitations and the characteristics of water compared to air, not all atmospheric flows can be simulated, and care must be taken to scale or nondimensionalize the results to make them independent of the working fluid. Compare large eddy simulation models, direct numerical simulation.