A semiempirical method of describing the mechanism of vertical turbulent mixing

On the basis of the experimental measurements of the level slope and the velocity profiles in artificial channels of the Volga River estuary an expression was obtained which relates the coefficient of vertical turbulent viscosity k sub z to the parameters of the mean movement: the mean local velocity and its vertical derivatives. The conclusion is drawn that k sub z is most closely interrelated to the square of the mean velocity. This conclusion and a number of other semiempirical expressions agree well with the theory of steady state turbulent currents. The applicability of the expression obtained for k sub z to the description of the turbulence in the drift type gradient currents of the shallow sea is checked. The calculation results and a qualitative discussion of them are presented.