Statistical properties of density fluctuations in the atmosphere

The improvement of the parametrix method for solving the full system of the Navier-Stokes is presented. As known the fundamental solution equation is an oscillatory one. These oscillations are observed while analyzing the density evolution. Their frequency diminishes as the time grows. The approximate expression is presented for density in the neighborhood of a vortical structure. The laser beam propagation has been analyzed. The method will enable to find time average quantities. We considered the mathematical theory of the laser-schlieren technique. Experimental data on grid-generated turbulence are presented.