Influence of the heating of a turbulent atmosphere by a light beam on the fluctuations of the beam intensity

A calculation is given of the changes in fluctuations of the temperature and permittivity of a turbulent atmosphere which is heated by a light beam. These changes are due, first, to the mixing of the atmosphere in the presence of fluctuations of the wind velocity and, secondly, to the nonuniform heating associated with random inhomogeneities of the refractive index. It is shown that the nonuniform heating is the more important effect. Random thermal lenses defocus the radiation in those regions where it would have been focused in a linear medium and this leads to a weakening of flucutations of the lightbeam intensity.