The Smagorinsky scheme in MOM provides expressions for horizontal momentum viscosity coefficients and horizontal tracer diffusivity coefficients. It does not provide expressions for vertical dissipation. The framework established by Smagorinsky dissipation allows for the general introduction of a non-constant viscosity coefficient in a physically consistent fashion, and the details for general non-constant viscosity are provided in Section 33.6. The values of the dissipation coefficients are based on a closure scheme which dissipates energy and tracer variance where the maximum dissipation acts on grid scale features. The fundamental ideas and history behind the method are nicely summarized in Smagorinsky (1993). For an alternative perspective, Leith (1996) has provided a critique of the Smagorinsky closure and argues for a form of dissipation based on ideas from two-dimensional turbulence.