Equations Governing the Mean Concentration of Species in Turbulence

Having demonstrated that exact solution for the mean concentrations (c, (x, t)) even of inert species in a turbulent fluid is not possible in general by either the Eulerian or Lagrangian approaches, we now consider what assumptions and approximations can be invoked to obtain practical descriptions of atmospheric diffusion. In Section 17.4 we shall proceed from the two basic equations for (c, ), (17.4) and (17.8), to obtain the equations commonly used for atmospheric diffusion. A particularly important aspect is the delineation of the assumptions and limitations inherent in each description. 

4 EQUATIONS GOVERNING THE MEAN CONCENTRATION OF SPECIES IN TURBULENCE 

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