AbstractA model is presented of the vertical structure of turbulence in the convective boundary layer. The model is based on representation of the fluctuating velocity components by trigonometric orthogonal functions. The vertical velocity component is represented by a sine and the horizontal by a cosine expansion. The sine representation of thewcomponent ensures thatw= 0 atz= 0. The expansion coefficients are uncorrelated if the sine functions are eigenfunctions of the vertical correlation function.A simple form, based on the inertial sub‐range, is adapted for the energy spectrum.Constant parameters of the model are evaluated from the surface layer measurements of the wind velocity variances, and it is shown that the model agrees with the measured vertical structure of variances through the whole boundary laye