Turbulent mixing in experimental

Mar Ecol Prog Ser 161: 265-293, 1997.Turbulent mixing is an integral aspect of aquatic ecosystems Turbulence affects ecosystem
features ranglng from phytoplankton blooms at large scales through microscale interactions in
the plankton. Enclosed experimental ecosystems, if they are to mimic the function of natural ecosystems, also must mimic natural turbulence and its effects. Large-scale velocity gradients and unstable buoyancy fluxes generate turbulent mixing in nature, most often at the surface and bottom boundaries and in the pycnocline. Large eddy sizes are controlled by the mixed layer depth, boundary layer thickness, or overturning length in the pycnocl~neT. urbulent energy cascades through smaller and smaller eddy scales until it can be dissipated by molecular viscosity at the smallest scales. In contrast, artificial apparatuses frequently are used to generate turbulent m~x i n gin the interior of experimental ecosystem enclosures.