Model for estimating the refractive-index structure constant in clear-air intermittent turbulence

We explain discrepancies in comparing estimations of the refractive-index structure constant C(n)(2) in clear air by means of different techniques by taking into account atmospheric intermittency effects. We formulate a model of C(n)(2) in intermittent turbulence on the basis of the Tatarskii theory, and we calculate the mean value of C(n)(2) through a probabilistic approach. We deduce a factor, which gives a measure of the statistical reduction of turbulence that is due to intermittency, within the model framework. A procedure for estimating the mean value of C(n)(2) from data of a specific radiosonde observation is illustrated.