A semiempirical theory is developed which relates the refractive-index-structure parameter <i>C<sub>n</sub></i><sup>2</sup> in the lowest few tens of meters to the vertical gradients of wind speed and temperature and to a stability parameter. This provides an indirect method of determining <i>C<sub>n</sub></i><sup>2</sup>, or its temperature counterpart <i>C<sub>T</sub></i><sup>2</sup>, and the method is successfully applied to recent data which include directly measured <i>C<sub>T</sub></i><sup>2</sup> values. The height dependence of the structure parameter is also determined, and the predicted <i>z</i><sup>-4/3</sup> profile under unstable conditions agrees with recent data in the free atmosphere at heights up to 500 m.
J. C. WYNGAARD, Y IZUMI, and STUART A. COLLINS, JR., "Behavior of the Refractive-Index-Structure Parameter near the Ground," J. Opt. Soc. Am. 61, 1646-1650 (1971)