Turbulence and atmospheric flow

A dimensionless measure of the role of viscosity in a particular flow is the Reynolds number. In geophysical situations, the turbulence intensity is likely to vary from place to place, violating the homogeneous assumption, and the three space dimensions are likely to behave differently so that the isotropic assumption is violated. The Kolmogorov result for homogeneous, isotropic three-dimensional turbulence is extremely straightforward. Virtually no other result in turbulence theory is so straightforward. One attractive approach would be simply to ignore the sub-gridscale Reynolds' stresses, that is, to show that they are negligible compared with the accelerations represented by the resolved terms of the equation.