Abstract: A technique for estimating eddy diffisivities in a turbulent atmospheric layer is presented. The scheme adopted is based on an inverse problem methodology. The inverse problem is formulated as a nonlinear constrained optimization problem, where the objective function is defined as the square differences between experimental and model data. The direct mathematical model is given by the advection-diffusion equation, which is solved by second order finite difference method. In the presence of noise is necessary to use some regularization term. The Tikhonov function and an entropic regularization of zeroth, first and second orders are used in this paper. In addition, two inversion strategies are used: alternate and simultaneous eddy diffusivities estimation. Numerical experiments show a good performance of the proposed methodology.