Application of a Thorpe Length Scale-based Approach for Estimating Refractive Index Structure Parameter Profiles in the Atmosphere

The spatio-temporal variation of optical turbulence is conventionally quantified by the structure parameter of the refractive index (C_n²). Over the years, numerous empirical and physically-based parameterizations have been proposed for the estimation of vertical profiles of C_n² in the troposphere and lower stratosphere. While the complexity of these approaches range vastly, not one has been deemed more superior over another. In this presentation, we describe a simple C_n² estimation approach using only temperature and pressure profiles as input. The most salient feature of this approach is the usage of the so-called Thorpe length scale as a surrogate for the outer length scale of turbulence. Utilizing an extensive worldwide database of C_n² profiles, measured via thermosonde balloon launches over decades, we document the strengths and weaknesses of our proposed approach.