ABSTRACT
Numerical simulation is a powerful tool to both understand and predict environmental flows. These flows are multiscale, e.g., a mesoscale eddy in the ocean has scales of motion that range from the eddy’s horizontal extent of say 100 km to the 1 cm scale at which molecular mixing is accomplished. Different spatial scales are governed by qualitatively different physical processes that include geostrophic flow, quasi-geostrophic turbulence, linear and nonlinear gravity waves, shear instabilities, convective instabilities, and three-dimensional (3D) turbulence. Time scales are similarly disparate, even if we exclude the interest in local variability of climate, and could range from months to hours to seconds.
